Tag Archive for: Greenbone

A new critical vulnerability of the highest possible severity score – CVE-2024-54085, CVSS 10 – has just been disclosed. It is found in the widely used American Megatrends’ (AMI) MegaRAC BMC (Baseboard Management Controller) software allowing authentication bypass and exploitation. Due to AMI’s dominant role in the motherboard supply chain, dozens of major hardware vendors are likely impacted. The vulnerability has a full technical explanation and proof-of-concept (PoC) further increasing the risk.

The PoC can effectively create a service account for the Redfish management console, and thus allows unauthenticated access to all remote BMC features. The exploit was verified against HPE Cray XD670, Asus RS720A-E11-RS24U, and ASRockRack. Other analysts have noted that although this CVE was released in 2025 its ID (CVE-2024-54085) was likely reserved in 2024.

CVE-2024-54085 allows an attacker to:

  • Exploit and remotely control a server
  • Install malware on the server including ransomware
  • Modify firmware for tampering
  • Potentially brick motherboard components (BMC or potentially BIOS/UEFI)
  • Cause physical damage via over-voltage
  • Induce indefinite reboot loops causing DoS conditions

Greenbone is able to detect affected servers with a remote vulnerability test that actively probes for a vulnerable BMC.

Potential Scope of the Impact

The particular interface for the MegaRAC BMC (Baseboard Management Controller), called Redfish, is just one of several BMCs that support remote server management. The Redfish standard has seen significant adoption in the enterprise server market as a modern replacement for legacy management interfaces like IPMI. This scope of the impact will include all products including OT, IoT or IT devices using AMI’s MegaRAC. When similar flaws were previously discovered in MegaRAC, the scope included products from Asus, Dell, Gigabyte, Hewlett Packard Enterprise, Lanner, Lenovo, NVIDIA and Tyan. AMI released patches on March 11, 2025, with HPE and Lenovo already issuing updates for affected.

A Technical Description of CVE-2024-54085

CVE-2024-54085 is a flaw in AMI’s SPx (Service Processor) firmware stack. More specifically SPx is part of AMI’s MegaRAC BMC solution. BMCs are microcontrollers embedded on a server’s motherboard that enable remote management and monitoring of the server, even when the system is powered off or unresponsive.

CVE-2024-54085 is classified as a “Authentication Bypass by Spoofing” [CWE-290] flaw. Using a client’s IP address for authentication is a typical scenario when CWE-290 occurs, since the source IP address can often be spoofed by the sender. Although AMI’s advisory is thin on details, Eclypsium researchers, attributed with the discovery, have provided a detailed article explaining the root cause. CVE-2024-54085 in fact does stem from using an IP address as a means for authentication. Redfish’s Lua-based access control logic uses HTTP headers, either the X-Server-Addr header or Host specification to determine whether an HTTP request is internal or external; automatically trusting internal requests as authenticated.

In BMC systems like MegaRAC, the “host interface” refers to a logical and physical connection between the BMC and the main server system (the host). For simplicity, this could be compared to the loopback interface (often named lo) with the IP address 127.0.0.1 and hostname localhost. In this case, the interface that communicates between the BMC chip and the host is assigned an address from the link-local IP range (169.254.0.0 to 169.254.255.255). Furthermore, this IP address is included in a list of trusted addresses during MegaRAC’s HTTP authentication process and successfully spoofing it results in authentication bypass. By reverse engineering the MegaRAC firmware, researchers discovered the link-local address 169.254.0.17 being used across several BMC chips.

The flaw also depends on the implementation of a regular expression that extracts all text from the X-Server-Addr header before the first colon character, and verifies if this text matches the trusted IPs stored in a Redis database. The BMC chips use Lighttpd as an embedded web server which was found to automatically add its own X-Server-Addr value. If a request already includes this header supplied by the client, Lighttpd appends its value after the user supplied one, allowing the attacker to provide a specially crafted header and control the value extracted by the regex. By supplying an X-Server-Addr value that matches the Host system’s link-local address, followed by a colon, (such as 169.254.0.17:) an attacker can trick the BMC into treating the request as though it comes from the internal host interface, bypassing authentication entirely.

Once authentication is bypassed, the rest of the HTTP request is processed, allowing the attacker to execute arbitrary API actions such as creating privileged accounts to gain full remote control over the server’s BMC and access its admin web-interface.

Steps for Mitigating CVE-2024-54085

Organizations must track their hardware vendor’s advisories closely and download the correct firmware updates when they become available. As a temporary safeguard, organizations can inspect their device manuals to determine if Redfish can be disabled if it’s not in use. Since BMCs can remain active even when the main server is powered down, affected systems must be treated as persistently exposed until the firmware is patched, unless Redfish is disabled, or the system is also air-gapped (disconnected from the network). Security teams may also develop new firewall rules or IPS rules to block attempts to exploit this flaw and protect vulnerable BMC management interfaces.

Because the flaw lies in an embedded proprietary firmware, patching is more complex than simply applying a routine operating system or application update. Unlike conventional software, BMC firmware resides on the motherboard’s dedicated chip. Therefore, BMC updates typically require a specialized software utility provided by the device vendor to “flash” the updated firmware. This process also results in downtime since administrators may need to boot into a special environment and reboot the system after the firmware update has been completed.

Summary

CVE-2024-54085 poses an extreme risk to enterprise infrastructure, allowing unauthenticated remote control of servers from major vendors like HPE and Lenovo. Given AMI’s dominant presence in data centers, exploitation could lead to mass outages, bricked hardware, or persistent downtime – making urgent detection and firmware patching essential for all affected systems.

Greenbone is able to detect affected servers with a remote vulnerability test that actively probes for an exploitable BMC interface.

CVE-2024-4577 (CVSS 9.8 Critical) is currently climbing the winners’ podium of the most malicious security vulnerabilities. Disclosed in early June 2024 by Devcore security researchers, weaponization began within a mere 48 hours. It is a PHP-CGI OS Command Injection vulnerability [CWE-78] impacting PHP for Windows. Attacks distributing “TellYouThePass” ransomware were immediately observed and the CVE added to CISA’s KEV list (Known Exploited Vulnerabilities of the Cybersecurity and Infrastructure Security Agency). Several months later, exploitation of CVE-2024-4577 suddenly continues to escalate.

Greenbone provided vulnerability tests (VTs) to detect systems impacted by CVE-2024-4577 since it was released in June 2024. This allows defenders to identify affected systems across public-facing or internal network infrastructure. Let’s look deeper into the threat of CVE-2024-4577.

Exploiting CVE-2024-4577 for RCE and Lateral Movement

Proof of concept (PoC) exploit code and a full technical breakdown has long been published by watchTowr Labs, and a Metasploit module was also released in mid-2024. National CERT advisories have recently been issued by CERT New Zealand (CERT NZ) and the Canadian Center for Cyber Security. However, the flaw had already been alerted by CERT-EU, and CERT-FR (French Government CERT) back in June 2024.

Due to CVE-2024-4577, the PHP-CGI (Common Gateway Interface) may misinterpret certain characters as PHP options, which may allow a malicious user to pass options to the php.exe binary. This trick can reveal the source code of scripts or run arbitrary PHP code on the server. CVE-2024-4577 is considered a bypass of a long-ago patched vulnerability in PHP, CVE-2012-1823.

In the case that attackers gain initial access to a victim’s network through social engineering or a different software vulnerability, CVE-2024-4577 can provide an attacker with the opportunity for lateral movement, or covert persistence, penetrating deeper into a victim’s infrastructure and increasing the blast radius of a cyber attack.

A Brief Technical Explanation of CVE-2024-4577

In a nutshell, exploitation of CVE-2024-4577 works by leveraging Unicode character conversion to inject malicious command-line arguments to the php.exe process. On a high-level, web servers behave differently when CGI mode is enabled. A webserver will normally parse HTTP requests and pass them to a PHP script for processing. However, when CGI mode is enabled, attributes are extracted from the URL and passed as arguments to the executable PHP binary (php.exe on Windows). This PHP-CGI process is known to introduce distinct security risks.

Although PHP-GCI is supposed to sanitize shell meta characters (such as hyphens, double-hyphens, ampersands, and equal signs) before being passed, this still opens a pathway to command injection if attackers can find a way to bypass the sanitization process. PHP-CGI encoding was also the target of exploiting CVE-2012-1823. Furthermore, similar character encoding battles are continuously waged resulting in new ways for attackers to execute XSS and SQL injection vulnerabilities.

In the current iteration of this attack, using a soft hyphen (0xAD) instead of a standard hyphen (0x2D), attackers can initiate PHP directives to achieve Remote Code Execution (RCE). This is because Windows uses the UCS-2 character set, converts all characters to the UCS-2 code-point value and also executes an additional “best-fit” conversion. In the case of CVE-2024-4577, it is the best-fit schema that converts soft hyphens into standard hyphens. This allows injecting php.exe with arguments to prepend and execute the HTTP request body itself by adding the command “-d allow_url_include=1 -d auto_prepend_file=php://input” using URL encoded soft hyphens to the HTTP GET string. Soft hyphens are typically invisible UTF-8 characters used to specify locations word breaks, but only when necessary to fit the text on the line. Thanks to Windows’ best-fit conversion, they are effectively converted into command line flags.

CVE-2024-4577 is Being Leveraged Globally in 2025

According to new reports released in March 2025, attacks leveraging CVE-2024-4577 are ongoing,  widespread and escalating. Cisco detected exploitation of CVE-2024-4577 in January 2025, targeting Japanese education, ecommerce and telecommunications companies. After gaining initial access via PHP, attackers installed Cobalt Strike’s ‘TaoWu’ plugins and modified Windows registry keys to establish persistent access through scheduled tasks.

Another recent report from GreyNoise reveals that mass exploitation of CVE-2024-4577 has extended to targets in the US, UK, Singapore, Indonesia, Taiwan, Hong Kong, India, Spain and Malaysia. Germany and China were reportedly the primary sources of attacks, accounting for 43% globally. GreyNoise also maintains a honeynet that detected over 1,089 unique IPs attempting exploitation in January 2025 alone, and counted 79 publicly available, specialized exploit kits. The cybersecurity firm warned of growing attack volume in February 2025, driven by automated scanning and signaling a rapidly escalating cyber threat.

Mitigation for CVE-2024-4577

CVE-2024-4577 affects all PHP versions (including PHP 5 and PHP 7 which are end-of-life) before 8.1.29, 8.2.20 and 8.3.8 on Windows. The best mitigation is to upgrade to a patched version with urgency. For environments where immediate patching isn’t feasible, defenders may disable the execution of PHP-CGI mode in favor of PHP-FPM (FastCGI Process Manager) or alternatively, utilize a web-application firewall (WAF) to filter and block exploitation attempts. PHP system administrators should also note several additional security risks associated with CGI and review them for optimal security.

Greenbone has provided vulnerability tests (VTs) to detect systems impacted by CVE-2024-4577 since it was first disclosed in June 2024. This early detection capability allows defenders to identify affected systems across public facing or internal network infrastructure. Greenbone’s detection tests include remote version detections [1][2], and a remote active check [3].

Summary

CVE-2024-4577 is a critical PHP-CGI vulnerability affecting PHP installations on Windows, that allows remote code execution (RCE). The flaw was weaponized within 48 hours of disclosure and used in TellYouThePass ransomware attacks. According to reports from Cisco and GreyNoise, mass exploitation of CVE-2024-4577 has been escalating globally, and multiple national CERT advisories have been issued. Defenders need to identify where affected products are operating within their infrastructure, and immediately update to a fixed version of PHP, disable PHP-CGI completely or switch to PHP-FPM (FastCGI Process Manager).

Two new CVEs in Apache Camel have been disclosed warranting immediate attention from users. On March 9, 2025, Apache disclosed CVE-2025-27636 (CVSS 5.6), a Remote Code Execution (RCE) flaw. Two days later, on March 11th, Akamai’s Security Intelligence Group (SIG) reported a bypass technique for the original patch, resulting in CVE-2025-29891 (CVSS 4.2) being published on March 12th.

Green graphic with stylised camel in a desert landscape. To the right is a button with the inscription ‘RCE in Apache Camel’.

Although the two vulnerabilities have only been assigned moderate CVSS severity scores by CISA-ADP (CISA’s Authorized Data Publisher), they could be severe impact vulnerabilities depending on the targeted Camel instance’s configuration. Both CVEs have the same root cause: improper filtering of HTTP headers or HTTP parameters when communicating to an Apache Camel instance. As the article’s title suggests, parameters were filtered using case-sensitive methods, while the arguments themselves were being applied in a non-case-sensitive manner.

Furthermore, publicly available proof-of-concept (PoC) code and a relatively complete technical description adds to the risk. Greenbone can detect both CVE-2025-27636 and CVE-2025-29891 with vulnerability tests that actively check for exploitable HTTP endpoints. Let’s review the details.

What Is Apache Camel?

Apache Camel is a popular open-source Java library for integrating different components of a distributed enterprise system architecture such as APIs or microservices. In a nutshell, Camel is a versatile platform for routing and mediation based on the Enterprise Integration Patterns (EIPs) concept of enterprise system architecture design. Apache Camel is heavily based on EIPs and provides an implementation of these patterns via its domain-specific languages (DSL) that include Java, XML, Groovy, YAML and others.

As of 2021, Apache Camel held approximately 3.03% of the Enterprise Application Integration market. The software is used by over 5,600 companies, roughly half being US-based. Camel’s market share is predominantly in the Information Technology and Services industry (33%), Computer Software industry (12%) and Financial Services industry (6%).

Two New CVEs in Apache Camel May Allow RCE

When any of Camel’s HTTP-based components handle requests, a default filter is supposed to prevent exposure of sensitive data or execution of internal commands. However, due to a flawed case-sensitive filtering rule, only exactly matched headers were filtered. However, downstream in the program logic, these headers were being applied in a non-case-sensitive manner, allowing filter bypass. Changing the case of the first character of the header name, an attacker could bypass the filter to inject arbitrary headers.

The good news is that either the camel-bean or camel-exec component must be enabled in combination with an http-based component such as such as camel-http, camel-http4, camel-rest, camel-servlet or others. Also, exploitation is limited to internal methods within the scope declared in the HTTP request URI. One final saving grace is that this flaw has not been implicated as an unauthenticated vulnerability. Therefore, unless the system designers have implemented any authentication and authorization for a Camel HTTP API, it is not exploitable.

At the high-end of the risk spectrum, if the Camel Exec component is enabled and targeted, an attacker can achieve arbitrary RCE as the user controlling the Camel process. RCE is achieved by sending the CamelExecCommandExecutable header to specify an arbitrary shell command, overriding the commands configured on the back-end. If exploitable Camel HTTP APIs are Internet accessible, the risk is especially high, however, this flaw could also be used for lateral movement within a network by an insider, or by attackers who have gained initial access to an organization’s internal network.

A technical description of the exploit chain and proof-of-concept (PoC) has been provided by Akamai.

What Is the Appropriate CVSS Score?

Although CVE-2025-27636 (CVSS 5.6) and CVE-2025-29891 (CVSS 4.2) have been assigned moderate severity scores, they could have a critical impact if either the camel-bean or camel-exec components are enabled in combination with http-based components. The situation highlights some limitations of the scoring by CVSS (Common Vulnerability Scoring System).

Akamai researchers report that the flaw is trivial to exploit and have published proof-of-concept (PoC) code, increasing the risk. This implies that the CVSS Attack Complexity (AC) metric should be set to Low (L). However, CISA-ADP has assessed attack complexity as high (AC:H) given these facts. Red Hat has accounted for these factors and increased the CVSS for CVE-2025-27636 to 6.3.

Also, the CISA-ADP assessed no impact to confidentiality for CVE-2025-29891, despite the potential for arbitrary RCE. However, if an Apache Camel instance has a vulnerable configuration, a high impact assessment for Confidentiality (C), Integrity (I) and Availability (A), is justified further increasing the criticality to CVSS 9.8.

On the other hand, the CISA-ADP assigned a Privileges Required (PR) value of None (N). However, although Akamai’s PoC does not use an HTTPS connection or authentication, it would be extremely negligent to operate an unencrypted and unauthenticated API. Apache Camel supports Java Secure Socket Extension (JSSE) API for Transport Layer Security (TLS) or using a KeyCloak Single Sign-On (SSO) authorization server. Camel instances with some form of client authentication enabled would be protected against exploitation. For most cases, the PR value should be adjusted to Low (L) or High (H) resulting in a diminished CVSS of 7.3 or 8.8.

Furthermore, the CVEs were assigned a Scope value Unchanged (UC). According to the CVSS v3.1 specification: “The Scope metric captures whether a vulnerability in one vulnerable component impacts resources in components beyond its security scope.” Execution of arbitrary shell commands on the compromised system is typically assigned the value of Changed (C). If the Camel process is owned by the Linux/Unix root or a Windows administrator user, an attacker would have virtually unlimited control of a compromised system. Accounting for the variety of possible CVSS assessments, CVE-2025-27636 and CVE-2025-29891 should be considered critical severity vulnerabilities if an instance meets the configuration requirements and does not apply authentication.

Mitigating the CVEs in Apache Camel

CVE-2025-27636 and CVE-2025-29891 affect Apache Camel version 4.10 before 4.10.2, version 4.8 before 4.8.5 and version 3 before 3.22.4. Users should upgrade to 4.10.2, 4.8.5 or 3.22.4 or implement custom header filtering using removeHeader or removeHeaders in Camel routes. It should be noted that Camel versions 4.10.0, 4.10.1, 4.8.0 to 4.8.4, and 3.10.0 to 3.22.3 are still vulnerable although they were considered security updates that addressed the flaw.

Also, it is strongly recommended that all HTTP endpoints in a distributed architecture employ strong authentication. For Apache Camel, options include: using Java Secure Socket Extension (JSSE) API for TLS with Camel components or using a KeyCloak OAuth 2.0 SSO authorization server. For legacy systems, a minimum of HTTP Basic Authentication should be configured.

Summary

Apache Camel users should immediately upgrade to versions 4.10.2, 4.8.5 or 3.22.4 to mitigate the newly published CVEs affecting Apache Camel. Alternatively, implement custom header filtering using removeHeader or removeHeaders in Camel routes. Strong authentication on all HTTP endpoints is also highly recommended for security best-practices. Apache Camel supports the JSSE API for TLS or KeyCloak SSO solutions. Greenbone is able to detect both CVE-2025-27636 and CVE-2025-29891 with vulnerability tests that actively check for exploitable HTTP endpoints.

Cyber threats are evolving at breakneck speed, but the fundamental weaknesses attackers exploit remain strikingly unchanged. So far in 2025, many analysts have published landscape reviews of 2024 and outlooks for 2025. The cost of cyber breaches is ticking upwards, but overall, cyber breach root-causes have not changed. Phishing [T1566] and exploiting known software vulnerabilities [T1190] continue to top the list. Another key observation is that attackers are weaponizing public information faster, converting CVE (Common Vulnerabilities and Exposures) disclosures into viable exploit code within days or even hours. Once inside a victim’s network, they are executing precision second-stage objectives faster too, deploying ransomware within minutes.

In this month’s edition of the Greenbone Threat Report, we will briefly review the disclosed chats of the Black Basta ransomware group and highlight Greenbone’s coverage of their now exposed techniques. We will also review a report from Greynoise about mass exploitation attacks, a new actively exploited vulnerability in Zimbra Collaboration Suite and new threats to edge networking devices.

The Era of Tectonic Technology

If security crises are like earthquakes, then the global tech ecosystem is the underlying tectonic plates. The global technology ecosystem would be best represented as the Paleozoic Era of geological history. Rapid innovative and competitive market forces are pushing and pulling at the fabric of IT security like the colliding supercontinents of Pangea; continuous earthquakes constantly forcing continental shift.

Entirely new paradigms of computing such as generative AI and quantum computing are creating advantages and risks; volcanoes of value and unstable ground. Global governments and tech giants are wresting for access to citizen’s sensitive personal data, adding gravity. These struggles have significant implications for privacy, security and how society will evolve. Here are some of the major forces destabilizing IT security today:

  • Rapidly evolving technologies are driving innovation, forcing technical change.
  • Organizations are both forced to change as technologies and standards depreciate and motivated to change to remain competitive.
  • Fierce market competition has accelerated product development and release cycles.
  • Strategic planned obsolescence has been normalized as a business strategy for reaping financial gain.
  • Pervasive lack of accountability for software vendors has led to prioritization of performance over “security-first” design principles.
  • Nation-states weaponize technology for Cyber Warfare, Information Warfare and Electronic Warfare.

Due to these forces, well-resourced and well-organized cyber criminals find a virtually unlimited number of security gaps to exploit. The Paleozoic Era lasted 300 million years. Hopefully, we won’t have to wait that long for product vendors to show accountability and employ secure design principles [1][2][3] to prevent so-called “unforgivable” vulnerabilities of negligence [4][5]. The takeaway is that organizations need to develop technical agility and efficient patch management programs. Continuous prioritized vulnerability management is a must.

Black Basta Tactics Revealed: Greenbone Has Coverage

Leaked internal chat logs belonging to Black Basta ransomware group have provided insight into the group’s tactics and inner workings. The logs were leaked by an individual using the alias “ExploitWhispers” who claimed the release was in response to Black Basta’s controversial targeting of Russian banks, allegedly creating internal conflicts within the group. Since its emergence in April 2022, Black Basta has reportedly amassed over $100 million in ransom payments from more than 300 victims worldwide. 62 CVEs referenced in leaked documents reveal the group’s tactics for exploiting known vulnerabilities. Of these 62, Greenbone maintains detection tests for 61, covering 98% of the CVEs.

The Greynoise 2025 Mass Exploitation Report

Mass exploitation attacks are fully automated network attacks against services that are accessible via internet. This month, Greynoise published a comprehensive report summarizing the mass exploitation landscape including the top CVEs attacked by the largest botnets (unique IPs), the most exploited product vendors and top CVEs included in the CISA’s (Cybersecurity and Infrastructure Security Agency) KEV (Known Exploited Vulnerabilities) catalog and exploited by botnets. Greenbone Enterprise Feed has detection tests for 86% of all CVEs (86 total) referenced in the report. When considering only CVEs issued in 2020 or later (66 total), our Enterprise Feed has 90% detection coverage.

Additional findings include:

  • 60% of CVEs exploited in mass exploitation attacks were published in 2020 or later.
  • Attackers are exploiting vulnerabilities within hours of disclosure.
  • 28% of vulnerabilities in CISA KEV are exploited by ransomware threat actors.

Zimbra Collaboration Suite

CVE-2023-34192 (CVSS 9.0) is a high-severity Cross-Site Scripting (XSS) vulnerability in Zimbra Collaboration Suite (ZCS) version 8.8.15. The flaw allows authenticated remote attackers to execute arbitrary code via crafted scripts targeting the `/h/autoSaveDraft` function. CISA added CVE-2023-34192 to its KEV catalog, indicating that it has been actively exploited in real-world attacks. Proof-of-concept (PoC) exploit code is publicly available, allowing low-skilled attackers to join the fray. CVE-2023-34192 has held a very high EPSS since its disclosure in 2023. For defenders leveraging EPSS for remediation prioritization, this indicates a high priority to patch.

Zimbra Collaboration Suite (ZCS) is an open-source office productivity platform that integrates email, calendar, contacts, tasks and collaboration tools but holds a niche market share of less than 1% of all email and messaging platforms.

Living on the Edge: New Critical Networking Device Flaws

In our monthly threat report we have been tracking the persistent threat to edge network devices. Earlier this-month, we reported on a perfect security storm affecting end-of-life (EOL) Zyxel routers and firewalls. In this section we will review new security risks that fall into the “edge networking” category. Greenbone has detection capabilities for all CVEs discussed below.

Chinese Hackers Exploit Palo Alto’s PAN-OS for Ransomware

CVE-2024-0012 (CVSS 9.8), a vulnerability in Palo Alto PAN-OS disclosed last November, is considered one of the most exploited vulnerabilities of 2024. The CVE is also reportedly being used by Chinese state-backed threat actors for ransomware attacks. Another new flaw affecting PAN-OS, CVE-2025-0108 (CVSS 9.1), was just disclosed this month and immediately tagged as actively exploited by CISA. CVE-2025-0108 is an authentication bypass in the management web-interface and can be chained together with CVE-2024-9474 (CVSS 7.2), a separate privilege escalation vulnerability to gain unauthenticated root control over an unpatched PAN-OS device.

SonicWall Patches a Critical Actively Exploited CVE in SonicOS

CVE-2024-53704, a critical severity vulnerability in SonicWall devices, has been recently added to CISA’s KEV list. Astoundingly, CISA lists 8 SonicWall CVEs that are known to be actively exploited in ransomware attacks. CVE-2024-53704 (CVSS 9.8) is an Improper Authentication vulnerability [CWE-287] in the SSLVPN authentication mechanism of SonicWall’s SonicOS versions 7.1.1-7058 and older, 7.1.2-7019, and 8.0.0-8035. It allows remote attackers to bypass authentication and and hijack active SSL VPN sessions, potentially gaining unauthorized network access. A full technical analysis is available from BishopFox. An advisory from SonicWall also names additional high severity CVEs in SonicOS that have been patched along with CVE-2024-53704.

Sophos’ CyberroamOS and EOL XG Firewalls Actively Exploited

Sophos, which acquired Cyberoam in 2014, has issued an alert and patch for CVE-2020-29574. CyberoamOS is part of Sophos’ product ecosystem. Aside from this CVE, Sophos XG Firewall, soon to be EOL, is also the subject of an active exploitation alert.

  • CVE-2020-29574 (CVSS 9.8): A critical SQL injection [CWE-89] vulnerability identified in the WebAdmin interface of CyberoamOS versions up to December 4, 2020. This flaw allows unauthenticated attackers to remotely execute arbitrary SQL statements, potentially gaining complete administrative access to the device. A hotfix patch has been issued, which also extends to some affected end-of-life (EOL) products.
  • CVE-2020-15069 (CVSS 9.8) is a critical Buffer Overflow vulnerability in Sophos XG Firewall versions 17.x through v17.5 MR12, allowing unauthenticated RCE via the HTTP/S Bookmarks feature for clientless access. This vulnerability, published in 2020 is now being actively exploited and has been added to CISA KEV indicating heightened risk. Sophos released an advisory in 2020 when the vulnerability was disclosed, along with a hotfix affected firewalls. The XG Series hardware appliances are soon scheduled to reach end-of-life (EOL) on March 31, 2025.

PrivEsc and Auth Bypasses in Fortinet FortiOS and FortiProxy

Fortinet disclosed two critical vulnerabilities, both affecting FortiOS and FortiProxy. The Canadian Center for Cybersecurity and the Belgian Center for Cybersecurity have issued advisories. Fortinet acknowledges active exploitation of CVE-2024-55591 and has released official guidance that includes details on affected versions and recommended updates. ​

  • CVE-2024-55591 (CVSS 9.8): An Authentication Bypass Using an Alternate Path or Channel vulnerability [CWE-288] affecting FortiOS allows a remote attacker to gain super-admin privileges via crafted requests to Node.js websocket module. Multiple PoC exploits are available [1][2] increasing the risk of exploitation by low-skilled attackers.
  • CVE-2024-40591 (CVSS 8.8): Allows an authenticated administrator with Security Fabric permissions to escalate their privileges to super-admin by connecting the targeted FortiGate device to a malicious upstream FortiGate under their control.

Cisco Flaws Implicated as Initial Access Vectors in Telecom Hacks

In the past few months, China’s Salt Typhoon espionage group has routinely exploited at least two critical vulnerabilities in Cisco IOS XE devices to gain persistent access to telecommunications networks. Victims include Italian ISP, a South African telecom, and a large Thai telecom, and twelve universities worldwide including UCLA, Indonesia’s Universitas Negeri Malang and Mexico’s UNAM among others. Previously, Salt Typhoon had compromised at least nine U.S. telecoms, including Verizon, AT&T and Lumen Technologies. U.S. authorities claim Salt Typhoon’s goal is surveilling high-profile individuals, political figures and officials related to Chinese political interests.

CVEs exploited by Salt Typhoon include:

  • CVE-2023-20198 (CVSS 10): A privilege escalation flaw in Cisco IOS XE’s web interface. Used for initial access, allowing attackers to create an admin account.
  • CVE-2023-20273 (CVSS 7.2): Another privilege escalation flaw, used after gaining admin access to escalate privileges to root and establish a GRE (Generic Routing Encapsulation) tunnel for persistence.

Also, two other CVEs in Cisco products entered the radar in February 2025:

  • CVE-2023-20118 (CVSS 7.2): A command injection vulnerability in the web-based management interface of Cisco Small Business Routers allows authenticated, remote attackers to execute arbitrary commands with root-level privileges by sending crafted HTTP requests. CISA added CVE-2023-20118 to its KEV catalog, indicating evidence of active exploitation.
  • CVE-2023-20026 (CVSS 7.2): A command injection vulnerability in the web-based management interface of Cisco Small Business Routers RV042 Series allows authenticated, remote attackers with valid administrative credentials to execute arbitrary commands on the device. The flaw is due to improper validation of user input within incoming HTTP packets. While CVE-2023-20026 is not known to be exploited in any active campaigns, Cisco’s Product Security Incident Response Team (PSIRT) is aware that PoC exploit code for this vulnerability exists.

Ivanti Patches Four Critical Flaws

Four critical vulnerabilities were identified, affecting Ivanti Connect Secure (ICS), Policy Secure (IPS), and Cloud Services Application (CSA). No reports of active attacks in the wild or PoC exploits have emerged yet. Ivanti advises users to promptly update to the newest versions to address these critical vulnerabilities.

Here is a brief technical summary:

  • CVE-2025-22467 (CVSS 8.8): Attackers with credentials can achieve remote code execution (RCE) due to a stack-based buffer overflow [CWE-121] flaw in ICS versions prior to 22.7R2.6.
  • CVE-2024-38657 (CVSS 9.1): Attackers with credentials can write arbitrary files due to an external control of file name vulnerability in ICS versions before 22.7R2.4 and IPS versions before 22.7R1.3.
  • CVE-2024-10644 (CVSS 9.1): A code injection flaw in ICS (pre-22.7R2.4) and IPS (pre-22.7R1.3), allows arbitrary RCE to authenticated administrators. ​
  • CVE-2024-47908 (CVSS 7.2): An operating system command injection vulnerability [CWE-78] in CSA’s admin web console (versions before 5.0.5), allows arbitrary RCE to authenticated administrators.

Summary

This month’s Threat Report highlights key cybersecurity developments, including the evolving tactics of ransomware groups like Black Basta and the pervasive critical threat to edge network devices. With the support of AI tools, attackers are exploiting vulnerabilities faster-sometimes within hours of disclosure. Organizations must remain vigilant by adopting proactive security measures, continuously updating their defenses and leveraging threat intelligence to stay ahead of emerging threats.

Every product has a due date, but customers often have little warning and no recourse when a vendor decides to sunset a product. Once a vendor designates a product as end-of-life (EOL) or end-of-service (EOS), managing associated risks becomes more complex. Risk is magnified when cyber criminals find and exploit vulnerabilities that will never be patched. If an EOL product becomes vulnerable in the future, its users need to implement additional security controls on their own.

Digital illustration of storm clouds and a trash bin with a router symbol, representing end-of-life IT products and increasing ransomware risks.

If the vendor is found to be still selling these vulnerable EOL products, it may be considered the “perfect storm” or the maximum disaster. In this article we will investigate several security alerts for Zyxel products including some designated EOL and another flaw exploited in ransomware attacks.

An Overview of Recent Vulnerabilities in Zyxel Products

CVE-2024-40891 (CVSS 8.8), a high severity Remote Code Execution (RCE) flaw in Zyxel’s telnet implementation has been known since mid-2024. Yet, almost six months later, Zyxel has not issued a patch, claiming the affected products are EOS and EOL. Early in 2025, Greynoise observed active exploitation of CVE-2024-40891 against vulnerable Zyxel CPE networking devices. That CVE (Common Vulnerabilities and Exposures) and another RCE flaw, CVE-2024-40890 (CVSS 8.8), were both added to CISA’s Known Exploited Vulnerabilities (KEV) list by mid-February. While both CVEs (Cybersecurity and Infrastructure Security Agency) were post-authentication RCE flaws, a third security gap, CVE-2025-0890 (CVSS 9.8), published on February 4th, provided the final piece to the puzzle: extremely weak default credentials for remotely accessible services – that is, on top of the already unencrypted Telnet authentication process.

Researchers at VulnCheck who originally discovered the flaws also pointed out that the vendor continues to sell the faulty devices despite being aware of active exploitation and having no intention to issue patches. As of February 25th, 2025, some of the affected products were still being sold from Zyxel’s official Amazon store [1][2]. On top of these, another vulnerability in Zyxel products, CVE-2024-11667, is being actively exploited in ransomware attacks by the Helldown threat actor.

In the telecom technologies sector, Zyxel holds an estimated market share of 4.19%, serving around 2,277 companies including the world’s biggest tech giants. Zyxel Group, headquartered in Hsinchu Science Park, Taiwan, is a prominent provider of networking solutions for both businesses and home users, operating globally in over 150 countries.

A Timeline of Events

  • 2024-07-13: VulnCheck notified Zyxel about vulnerabilities in CPE series products.
  • 2024-07-31: VulnCheck published information about CVE-2024-40890 and CVE-2024-40891 on their blog.
  • 2025-01-28: Active exploitation of CVE-2024-40891 was reported by GreyNoise.
  • 2025-02-03: VulnCheck released further information highlighting the risk presented by Zyxel’s position and providing evidence that vulnerable devices were still being sold online by the vendor.
  • 2025-02-04: Zyxel released a security advisory labelling affected products as EOL and stating they will not receive updates.

Technical Descriptions of Recent Zyxel Vulnerabilities

Aside from Zyxel’s slow response to security researchers and their decision to continue selling EOL products with exploitable vulnerabilities, there are additional lessons to learn from a technical assessment of the flaws themselves. Namely, how product vendors continue to market products with unforgivable security flaws while skirting accountability.                                                                                

  • CVE-2024-40891 (CVSS 8.8 High): Authenticated users can exploit Telnet command injection due to improper input validation in `libcms_cli.so`. Commands are passed unchecked to a shell execution function, allowing arbitrary RCE. Aside from checking that the command string starts with an approved command, the `prctl_runCommandInShellWithTimeout` function has no filtering, allowing command chaining and arbitrary command injection.
  • CVE-2024-40890 (CVSS 8.8 High): A post-authentication command injection vulnerability in the CGI program of the legacy DSL Zyxel VMG4325-B10A firmware version 1.00(AAFR.4)C0_20170615 could allow an authenticated attacker to execute operating system (OS) commands on an affected device by sending a crafted HTTP POST request.
  • CVE-2025-0890 (CVSS 9.8 Critical): Devices use weak default credentials such as usernames and passwords admin:1234, zyuser:1234, and supervisor:zyad1234. None of these accounts are visible via the web interface but can be found in the device’s `/etc/default.cfg` These default credentials are now well-known by attackers. The “supervisor” and “zyuser” accounts can both access devices remotely via Telnet. “supervisor” has hidden privileges, granting full system access, while “zyuser” can still exploit CVE-2024-40891 for RCE. Use of such default credentials violate CISA’s Secure by Design pledge and the EU’s upcoming Cyber Resilience Act (CRA).

The affected products include Zyxel VMG1312-B Series (VMG1312-B10A, VMG1312-B10B, VMG1312-B10E, VMG3312-B10A, VMG3313-B10A, VMG3926-B10B, VMG4325-B10A, VMG4380-B10A, VMG8324-B10A, VMG8924-B10A) and two Zyxel Business Gateway Series routers (SBG3300, and SBG3500). The Zyxel CPE (Customer Premises Equipment) series devices are designed for home and small business internet connectivity, such as DSL, fiber and wireless gateways. As such, they are typically installed at a customer’s location to connect them to an Internet  Service Provider’s (ISP) network and are therefore not easily protected from the Internet by firewalls. Considering the nature of Zyxel CPE devices and the vulnerabilities in question, it would not be surprising if tens of thousands or more Zyxel devices were participating in malicious botnet activity.

Greenbone is able to detect EOL Zyxel devices that are vulnerable to the aforementioned CVEs.

CVE-2024-11667: Zyxel Firewalls Exploited in Ransomware Attacks

CVE-2024-11667 (CVSS 9.8 Critical), published in late December 2024, is a path traversal flaw [CWE-22] in the web-management console of Zyxel ATP and USG FLEX firewall series. The vulnerability is known to be exploited by the Helldown threat actor in ransomware attacks and the subject of several national cybersecurity advisories [1][2].

The Helldown ransomware group emerged in August 2024 as a notable threat actor in the cybersecurity landscape. This group employs a double extortion strategy, wherein they exfiltrate sensitive data from targeted organizations and subsequently deploy ransomware to encrypt the victims’ systems. If the ransom demands are not met, Helldown threatens to publicly release the stolen data on their data leak site. In addition to exploiting these Zyxel flaws, Helldown is known to exploit Windows OS vulnerabilities, VMware ESX,  and Linux environments, often using compromised VPN credentials to move laterally within networks.

Zyxel has released an advisory acknowledging the ransomware attacks and patches for affected products. Greenbone is able to detect Zyxel products affected by CVE-2024-11667 with three separate product specific version detection tests [1][2][3].

Summary

The situation with Zyxel seems to be a perfect storm leading to an important question: What recourse do customers have when a vendor fails to patch a security gap in their product? Zyxel’s EOL networking devices remain actively exploited, with vulnerabilities that can be combined for unauthorized arbitrary RCE and other unauthorized actions. CVE-2024-40891, CVE-2024-40890, and CVE-2025-0890 are now in CISA’s KEV list, while CVE-2024-11667 has been linked to ransomware attacks. The researchers from VulnCheck, who discovered several of these CVEs, have criticized Zyxel for poor communication and further for selling unpatched EOL devices. Greenbone detects affected products enabling a proactive approach to vulnerability management and the opportunity for users to mitigate exposure.

Trimble Cityworks, an enterprise asset management (EAM) and public works management software is actively under attack. The campaign began as an unknown (zero-day) vulnerability, but is now tracked as ​​CVE-2025-0994 with a CVSS of 8.6. The vulnerability is a deserialization flaw [CWE-502] that could allow an authenticated attacker to execute arbitrary code remotely (Remote Code Execution; RCE). Greenbone includes detection for CVE-2025-0994 in the Enterprise Feed.

Active exploitation of CVE-2025-0994 is a real and present danger. Trimble has released a statement acknowledging the attacks against their product. Thanks to the vendor’s transparency, CISA (Cybersecurity and Infrastructure Security Agency) has added CVE-2025-0994 to their catalog of Known Exploited Vulnerabilities (KEV), published an ICS advisory as well as a CSAF 2.0 document. CSAF 2.0 advisories are machine readable advisory documents for decentralized sharing of cybersecurity intelligence.

Although many media reports and some threat platforms indicate that a public proof-of-concept (PoC) exists, the only search result for GitHub is simply a version detection test. This means it is less likely that low-skilled hackers will easily participate in attacks. The misinformation is likely due to poorly designed algorithms combined with lack of human oversight before publishing threat intelligence.

Who Is at Risk due to CVE-2025-0994?

Trimble Cityworks is designed for and used primarily by local governments and critical infrastructure providers including water and wastewater systems, energy, transportation systems, government industrial facilities and communications agencies. Cityworks enhances Geographic Information Systems (GIS) by integrating asset management and public works solutions directly with Esri ArcGIS. The software is meant to help organizations manage infrastructure, schedule maintenance and improve operational efficiency. In addition to CISA, several other government agencies have issued alerts regarding this vulnerability including the US Environment Protection Agency (EPA), the Canadian Centre for Cyber Security and New York State.

Trimble Cityworks has reported serving over 700 customers across North America, Europe, Australia and the Middle East in 2019. While specific numbers for municipal governments in the U.S., Canada and the EU are not publicly disclosed, a Shodan search and Censys map both reveal only about 100 publicly exposed instances of Cityworks. However, the application is considered to have a high adoption rate by local governments and utilities. If publicly exposed, CVE-2025-0994 could offer an attacker initial access [T1190]. For attackers who already have a foothold, the flaw is an opportunity for lateral movement [TA0008] and presents an easy mark for insider attacks.

A Technical Description of CVE-2025-0994

CVE-2025-0994 is a deserialization vulnerability [CWE-502] found in versions of Trimble Cityworks prior to 15.8.9 and Cityworks with Office Companion versions prior to 23.10. The vulnerability arises from the improper deserialization of untrusted serialized data, allowing an authenticated attacker to execute arbitrary code remotely on a target’s Microsoft Internet Information Services (IIS) web server.

Serialization is a process whereby the software code or objects are encoded to be transferred between applications and then reconstructed into the original format used by a programming language. When Trimble Cityworks processes serialized objects, it does not properly validate or sanitize untrusted input. This flaw allows an attacker with authenticated access to send specially crafted serialized objects, which can trigger arbitrary code execution on the underlying IIS server. Deserializing data from unauthenticated sources seems like a significant design flaw in itself, but failing to properly sanitize serialized data is especially poor security.

Exploitation CVE-2025-0994 could lead to:

  • Unauthorized access to sensitive data
  • Service disruption of critical infrastructure systems
  • Potential full system compromise of the affected IIS web server

Mitigating CVE-2025-0994 in Trimble Cityworks

Trimble has released patched versions of Cityworks that address the deserialization vulnerability. These patches include Cityworks 15.8.9 and Cityworks 23.10. On-premise users must immediately upgrade to the patched version, while Cityworks Online (CWOL) customers will receive these updates automatically.

Trimble noted that some on-premise deployments are running IIS with overprivileged identity permissions, which increases the attack surface. IIS should not have local or domain-level administrative privileges. Follow Trimble’s guidance in the latest Cityworks release notes to adjust IIS identity configurations properly.

Users of on-premises Trimble Cityworks should:

  • Update Cityworks 15.x versions to 15.8.9 and 23.x versions to 23.10.
  • Audit IIS identity permissions to ensure that they align with the principle of least privilege.
  • Limit attachment directory root configuration to only folders which only contain attachments.
  • Use a firewall to restrict IIS server access to trusted internal systems only.
  • Use a VPN to allow remote access to Cityworks rather than publicly exposing the service.

Summary

CVE-2025-0994 represents a serious security risk to Trimble Cityworks users, which largely comprise government and critical infrastructure environments. With active exploitation already observed, organizations must prioritize immediate patching and implement security hardening measures to mitigate the risk. Greenbone has added detection for CVE-2025-0994 to the Enterprise Feed, allowing customers to gain visibility into their exposure.

ITASEC, Italy’s most important conference for cyber security, takes place in Bologna from February 3 to 8, 2025. As a platinum sponsor, Greenbone is sending a strong signal for European cooperation and digital security. This step demonstrates our commitment to a global presence and direct customer interaction.

Street scene in the old town of Bologna with a view of the medieval 'Due Torri' towers, venue of the IT security conference ITASEC 2025

The “Due Torri”, two medieval towers, shape the image of the historic old town of Bologna. (Photo: Markus Feilner, CC-BY 2016)

 

New Perspectives in Italy and Worldwide

“At Greenbone, we are increasingly realizing how important our vulnerability management is for customers throughout Europe and how important it is for these customers to be able to communicate with us directly on site,” explains Chief Marketing Officer Elmar Geese. To meet this demand, Greenbone has established the Italian subsidiary OpenVAS S.R.L. At the same time, Greenbone is expanding into other regions. A new subsidiary in the Netherlands and an increased engagement in the Asian market are on the agenda.

We will not only be present at ITASEC with a booth, but will also contribute to the content: Dirk Boeing, Senior Consultant and cybersecurity expert at Greenbone, will speak on February 6th at 11:00 a.m. on the panel “Security Management in the NIS2 Era”.

Visit Us in Bologna!

The annual ITASEC takes place on the campus of the “Alma Mater Studiorum Università di Bologna”, the oldest university in Europe, which has been writing science history since 1088 – an ideal place for a conference dedicated to security in the digital future. The fair is organized by the CINI Cybersecurity National Lab, with a special focus in 2025 on the topic of security and rights in cyberspace. This is also reflected in the cooperation with the SERICS conference (Security and Rights in the Cyber Space), which is supported by the SERICS foundation as part of the almost 200 billion euro Italian „National Recovery and Resilience Plan“ (NRRP).

ITASEC at the University of Bologna offers an excellent opportunity to experience Greenbone live and learn more about our solutions. And this is just the beginning: in 2025 we will be in Italy, for example, at CyberSec Italia in Rome on March 5 and 6. And from March 18 to 19, Greenbone will be at the „Digitaler Staat“ congress in Berlin, and from March 19 at secIT in Hanover. We look forward to your visit!

In 2024, geopolitical instability, marked by conflicts in Ukraine and the Middle East, emphasized the need for stronger cybersecurity in both the public and private sector. China targeted U.S. defense, utilities, internet providers and transportation, while Russia launched coordinated cyberattacks on U.S. and European nations, seeking to influence public opinion and create discord among Western allies over the Ukrainian war. As 2024 ends, we can look back at a hectic cybersecurity landscape on the edge.

2024 marked another record setting year for CVE (Common Vulnerabilities and Exposures) disclosures. Even if many are so-called “AI Slop” reports [1][2], the sheer volume of published vulnerabilities creates a big haystack. As IT security teams seek to find high-risk needles in a larger haystack, the chance of oversight becomes more prevalent. 2024 was also a record year for ransomware payouts in terms of volume and size, and Denial of Service (DoS) attacks.

It also saw the NIST NVD outage, which affected many organizations around the world including security providers. Greenbone’s CVE scanner is a CPE (Common Platform Enumeration) matching function and has been affected by the NIST NVD outage. However, Greenbone’s primary scanning engine, OpenVAS Scanner, is unaffected. OpenVAS actively interacts directly with services and applications, allowing Greenbone’s engineers to build reliable vulnerability tests using the details from initial CVE reports.

In 2025, fortune will favor organizations that are prepared. Attackers are weaponizing cyber-intelligence faster; average time-to-exploit (TTE) is mere days, even hours. The rise of AI will create new challenges for cybersecurity. Alongside these advancements, traditional threats remain critical for cloud security and software supply chains. Security analysts predict that fundamental networking devices such as VPN gateways, firewalls and other edge devices will continue to be a hot target in 2025.

In this edition of our monthly Threat Report, we review the most pressing vulnerabilities and active exploitation campaigns that emerged in December 2024.

Mitel MiCollab: Zero-Day to Actively Exploited in a Flash

Once vulnerabilities are published, attackers are jumping on them with increased speed. Some vulnerabilities have public proof of concept (PoC) exploit code within hours, leaving defenders with minimal reaction time. In early December, researchers at GreyNoise observed exploitation of Mitel MiCollab the same day that PoC code was published. Mitel MiCollab combines voice, video, messaging, presence and conferencing into one platform. The new vulnerabilities have drawn alerts from the Belgian national Center for Cybersecurity, the Australian Signals Directorate (ASD) and the UK’s National Health Service (NHS) in addition to the American CISA (Cybersecurity and Infrastructure Security Agency). Patching the recent vulnerabilities in MiCollab is considered urgent.

Here are details about the new actively exploited CVEs in Mitel MiCollab:

  • CVE-2024-41713 (CVSS 7.8 High): A path traversal vulnerability in the NuPoint Unified Messaging (NPM) component of Mitel MiCollab allows unauthenticated path traversal by leveraging the “…/” technique in HTTP requests. Exploitation can expose highly sensitive files.
  • CVE-2024-35286 (CVSS 10 Critical): A SQL injection vulnerability has been identified in the NPM component of Mitel MiCollab which could allow a malicious actor to conduct a SQL injection attack.

Since mid-2022, CISA has tracked three additional actively exploited CVEs in Mitel products which are known to be leveraged in ransomware attacks. Greenbone is able to detect endpoints vulnerable to these high severity CVEs with active checks [4][5].

Array Networks SSL VPNs Exploited by Ransomware

CVE-2023-28461 (CVSS 9.8 Critical) is a Remote Code Execution (RCE) vulnerability in Array Networks Array AG Series and vxAG SSL VPN appliances. The devices, touted by the vendor as a preventative measure against ransomware, are now being actively exploited in recent ransomware attacks. Array Networks themselves were breached by the Dark Angels ransomware gang earlier this year [1][2].

According to recent reports, Array Networks holds a significant market share in the Application Delivery Controller (ADC) market. According to the ​​IDC’s WW Quarterly Ethernet Switch Tracker, they are the market leader in India, with a market share of 34.2%. Array Networks has released patches for affected products running ArrayOS AG 9.4.0.481 and earlier versions. The Greenbone Enterprise Feed has included a detection test for CVE-2023-28461 since it was disclosed in late March 2023.

CVE-2024-11667 in Zyxel Firewalls

CVE-2024-11667 (CVSS 9.8 Critical) in Zyxel firewall appliances are being actively exploited in ongoing ransomware attacks. A directory traversal vulnerability in the web management interface could allow an attacker to download or upload files via a maliciously crafted URL. Zyxel Communications is a Taiwanese company specializing in designing and manufacturing networking devices for businesses, service providers and consumers. Reports put Zyxel’s market share at roughly 4.2% of the ICT industry with a diverse global footprint including large Fortune 500 companies.

A defense in depth approach to cybersecurity is especially important in cases such as this. When attackers compromise a networking device such as a firewall, typically they are not immediately granted access to highly sensitive data. However, initial access allows attackers to monitor network traffic and enumerate the victim’s network in search of high value targets.

Zyxel advises updating your device to the latest firmware, temporarily disabling remote access if updates cannot be applied immediately and applying their best practices for securing distributed networks. CVE-2024-11667 affects Zyxel ATP series firmware versions V5.00 through V5.38, USG FLEX series firmware versions V5.00 through V5.38, USG FLEX 50(W) series firmware versions V5.10 through V5.38 and USG20(W)-VPN series firmware versions V5.10 through V5.38. Greenbone can detect the vulnerability CVE-2024-11667 across all affected products.

Critical Flaws in Apache Struts 2

CVE-2024-53677 (CVSS 9.8 Critical), an unrestricted file upload [CWE-434] flaw affecting Apache Struts 2 allows attackers to upload executable files into web-root directories. If a web-shell is uploaded, the flaw may lead to unauthorized Remote Code Execution. Apache Struts is an open-source Java-based web-application framework widely used by the public and private sectors including government agencies, financial institutions and other large organizations [1]. Proof of concept (PoC) exploit code is publicly available, and CVE-2024-53677 is being actively exploited increasing its risk.

The vulnerability was originally tracked as CVE-2023-50164, published in December 2023 [2][3]. However, similarly to a recent flaw in VMware vCenter, the original patch was ineffective resulting in the re-emergence of vulnerability. CVE-2024-53677 affects the FileUploadInterceptor component and thus, applications not using this module are unaffected. Users should update their Struts2 instance to version 6.4.0 or higher and migrate to the new file upload mechanism. Other new critical CVEs in popular open-source software (OSS) from Apache:

The Apache Software Foundation (ASF) follows a structured process across its projects that encourages private reporting and releasing patches prior to public disclosure so patches are available for all CVEs mentioned above. Greenbone is able to detect systems vulnerable to CVE-2024-53677 and other recently disclosed vulnerabilities in ASF Foundation products.

Palo Alto’s Secure DNS Actively Exploited for DoS

CVE-2024-3393 (CVSS 8.7 High) is a DoS (Denial of Service) vulnerability in the DNS Security feature of PAN-OS. The flaw allows an unauthenticated attacker to reboot PA-Series firewalls, VM-Series firewalls, CN-Series firewalls and Prisma Access devices via malicious packets sent through the data plane. By repeatedly triggering this condition, attackers can cause the firewall to enter maintenance mode. CISA has identified CVE-2024-3393 vulnerability as actively exploited and it’s among five other actively exploited vulnerabilities in Palo Alto’s products over only the past two months.

According to the advisory posted by Palo Alto, only devices with a DNS Security License or Advanced DNS Security License and logging enabled are affected. It would be an easy assumption to say that these conditions mean that top-tier enterprise customers are affected. Greenbone is able to detect the presence of devices affected by CVE-2024-3393 with a version detection test.

Microsoft Security in 2024: Who Left the Windows Open?

While it would be unfair to single out Microsoft for providing vulnerable software in 2024, the Redmond BigTech certainly didn’t beat security expectations. A total of 1,119 CVEs were disclosed in Microsoft products in 2024; 53 achieved critical severity (CVSS > 9.0), 43 were added to CISA’s Known Exploited Vulnerabilities (KEV) catalog, and at least four were known vectors for ransomware attacks. Although the comparison is rough, the Linux kernel saw more (3,148) new CVEs but only three were rated critical severity and only three were added to CISA KEV. Here are the details of the new actively exploited CVEs in Microsoft Windows:

  • CVE-2024-35250 (CVSS 7.8 High): A privilege escalation flaw allowing an attacker with local access to a system to gain system-level privileges. The vulnerability was discovered in April 2024, and PoC exploit code appeared online in October.
  • CVE-2024-49138 (CVSS 7.8 High): A heap-based buffer overflow [CWE-122] privilege escalation vulnerability; this time in the Microsoft Windows Common Log File System (CLFS) driver. Although no publicly available exploit exists, security researchers have evidence that this vulnerability can be exploited by crafting a malicious CLFS log to execute privileged commands at the system privilege level.

Detection and mitigation of these new Windows CVEs is critical since they are actively under attack. Both were patched in Microsoft’s December patch release. Greenbone is able to detect CVE-2024-35250 and CVE-2024-49138 as well as all other Microsoft vulnerabilities published as CVEs.

Summary

2024 highlighted the continuously challenging cybersecurity landscape with record-setting vulnerability disclosures, ransomware payouts, DoS attacks and an alarming rise in active exploitations. The rapid weaponization of vulnerabilities emphasizes the need for a continuous vulnerability management strategy and a defense-in-depth approach.

December saw new critical flaws in Mitel, Apache and Microsoft products. More network products: Array Networks VPNs and Zyxel firewalls are now being exploited by ransomware threat actors underscoring the urgency for proactive patching and robust detection measures. As we enter 2025, fortune will favor those prepared; organizations must stay vigilant to mitigate risks in an increasingly hostile cyber landscape.

An actively exploited RCE (Remote Code Execution) with system privileges vulnerability that does not require user-interaction is as bad as it gets from a technical standpoint. When that CVE impacts software widely used by Fortune 500 companies, it is a ticking time bomb. And when advanced persistent threat actors jump on a software vulnerability such as this, remediation needs to become an emergency response effort. Most recently, CVE-2024-50623 (also now tracked as CVE-2024-55956) affecting more than 4,200 users of Cleo’s MFT (Managed File Transfer) software met all these prerequisites for disaster. It has been implicated in active ransomware campaigns affecting several Fortune 500 companies taking center stage in cybersecurity news.

In this cybersecurity alert, we provide a timeline of events related to CVE-2024-50623 and CVE-2024-55956 and associated ransomware campaigns. Even if you are not using an affected product, this will give you valuable insight into the vulnerability lifecycle and the risks of third-party software supply chains. 

CVE-2024-50623 and CVE-2024-55956: a Timeline of Events

The vulnerability lifecycle is complex. You can review our previous article about next-gen vulnerability management for an in depth explanation on how this process happens. In this report, we will provide a timeline for the disclosure and resolution of CVE-2024-50623 and subsequently CVE-2024-55956 as a failed patch attempt from the software vendor Cleo was uncovered and exploited by ransomware operators. Our Greenbone Enterprise Feed includes detection modules for both CVEs [1][2], allowing organizations to identify vulnerable systems and apply emergency remediation. Here is a timeline of events so far:

  • October 28, 2024: CVE-2024-50623 (CVSS 10 Critical) affecting several Cleo MFT products was published by the vendor and a patched version 5.8.0.21 was
  • November 2024: CVE-2024-50623 was exploited for data exfiltration impacting at least 10 organizations globally including Blue Yonder, a supply chain management service used by Fortune 500 companies.
  • December 3, 2024: Security researchers at Huntress identified active exploitation of CVE-2024-50623 capable of bypassing the original patch (version 5.8.0.21).
  • December 8, 2024: Huntress observed a significant uptick in the rate of exploitation. This could be explained by the exploit code being sold in a Malware as a Service cyber crime business model or simply that the attackers had finished reconnaissance and launched a widespread campaign for maximum impact.
  • December 9, 2024: Active exploitation and proof-of-concept (PoC) exploit code was reported to the software vendor Cleo.
  • December 10, 2024: Cleo released a statement acknowledging the exploitability of their products despite security patches and issued additional mitigation guidance.
  • December 11, 2024: Wachtowr Labs released a detailed technical report describing how CVE-2024-50623 allows RCE via Arbitrary File Write [CWE-434]. Cleo updated their mitigation guidance and released a subsequent patch (version 5.8.0.24).
  • December 13, 2024: A new name, CVE-2024-55956 (CVSS 10 Critical), was issued for tracking this ongoing vulnerability, and CISA added the flaw to its Known Exploited Vulnerabilities (KEV) catalog, flagged for use in ransomware attacks.

Cleo Products Leveraged in Ransomware Attacks

The risk to global business posed by CVE-2024-50623 and CVE-2024-55956 is high. These two CVEs potentially impact more than 4,200 customers of Cleo LexiCom, a desktop-based client for communication with major trading networks, Cleo VLTrader, a server-level solution tailored for mid-enterprise organizations, and Cleo Harmony for large enterprises.

The CVEs have been used as initial access vectors in a recent ransomware campaign. The Termite ransomware operation [1][2] has been implicated in the exploitation of Blue Yonder, a Panasonic subsidiary in November 2024. Blue Yonder is a supply chain management platform used by large tech companies including Microsoft, Lenovo, and Western Digital, and roughly 3,000 other global enterprises across many industries; Bayer, DHL, and 7-Eleven to name a few. Downtime of Blue Yonder’s hosted service caused payroll disruptions for StarBucks. The Clop ransomware group has also claimed responsibility for recent successful ransomware attacks.

In the second stage of some breaches, attackers conducted Active Directory domain enumeration [DS0026], installed web-shells [T1505.003] for persistence [TA0003], and attempted to exfiltrate data [TA0010] from the victim’s network after gaining initial access via RCE. An in-depth technical description of the Termite ransomware’s architecture is also available.

Mitigating CVE-2024-50623 and CVE-2024-55956

Instances of Cleo products version 5.8.0.21 are still vulnerable to cyber attacks. The most recent patch, version 5.8.0.24 is required to mitigate exploitation. All users are urged to apply updates with urgency. Additional mitigation and best practices include disabling the autorun functionality in Cleo products, removing access from the Internet or using firewall rules to restrict access to only authorized IP addresses, and blocking the IP addresses of endpoints implicated in the attacks.

Summary

Cleo Harmony, VLTrader, and LexiCom prior to version 5.8.0.24 are under active exploitation due to critical RCE vulnerabilities (CVE-2024-50623 and CVE-2024-55956). These flaws have been the entry point for successful ransomware attacks against at least 10 organizations and impacting Fortune 500 companies. Greenbone provides detection for affected products and affected users are urged to apply patches and implement mitigation strategies, as attackers will certainly continue to leverage these exploits.

Web browsers are a primary gateway to business and consequently they are also a primary gateway for cyber attacks. Malware targeting browsers could gain direct unauthorized access to a target’s network and data or social engineer victims into providing sensitive information that gives the attacker unauthorized access, such as account credentials. In 2024, major browsers (Chrome, Firefox, and Safari) accounted for 59 Critical severity (CVSS3 ³ 9) and 256 High severity (CVSS3 between 7.0 and 8.9) vulnerabilities. 10 CVEs (Common Vulnerabilities and Exposures) in the trifecta were added to the KEV (Known Exploited Vulnerabilities) catalog of CISA (Cybersecurity & Infrastructure Security Agency). Browser security should therefore be top-of-mind for security teams.

In light of this, we are proud to announce the addition of CIS Google Chrome Benchmark v3.0.0 Level 1 auditing to our list of compliance capabilities. This latest feature allows our Enterprise feed subscribers to verify their Google Chrome configurations against the industry-leading CIS compliance framework of the CIS (Center for Internet Security). The new Google Chrome benchmark tests will sit among our other CIS controls in critical cybersecurity areas such as Apache, IIS, NGINX, MongoDB, Oracle, PostgreSQL, Windows and Linux [1] [2].

CIS Google Chrome Benchmark for Windows

The CIS Google Chrome Benchmark v3.0.0 Level 1 is now available in the Greenbone Enterprise Feed. It establishes a hardened configuration for the Chrome browser. For Windows, implementing the controls involves setting Windows registry keys to define Chrome’s security configuration. Continuous attestation is important because if modified at the user level Chrome becomes more vulnerable to data-leakage, social engineering attacks or other attack vectors.

Our Enterprise vulnerability feed uses compliance policies to run tests on target endpoints, verifying each requirement in the CIS benchmark through one or more dedicated vulnerability tests. These tests are grouped into scan configurations which can be used to create scan tasks that access groups of target systems to verify their security posture. When aligning with internal risk requirements or mandatory government policies, Greenbone has you covered.

The Importance of Browser Security

Much of the critical information flowing through the average organization is transmitted through the browser. The rise of a remote workforce and cloud-based web-applications means that web browsers are a primary interface for business activities. Not surprisingly, in the past few years, Internet browsers have been a hotbed for exploitation. National cybersecurity agencies such Germany’s BSI [3] [4], CISA [5] [6], and the Canadian Centre for Cyber Security [7] have all released advisories for addressing the risks posed by Internet browsers.

Browsers can be exploited via technical vulnerabilities and misconfigurations that could lead to remote code execution, theft of sensitive data and account takeover, but are also a conduit for social engineering attacks. Browser security must be addressed by implementing a hardened security profile and continuously attesting it and by regularly applying updates to combat any recently discovered vulnerabilities. Greenbone is able to detect known vulnerabilities for published CVEs in all major browsers and now with our latest CIS Google Chrome Benchmark certification, we can attest industry standard browser compliance.

How Does the CIS Google Chrome Benchmark Improve Browser Security?

Every CIS Benchmark is developed through a consensus review process that involves a global community of subject matter experts from diverse fields such as consulting, software development, auditing, compliance, security research, operations, government, and legal. This collaborative process is meant to ensure that the benchmarks are practical and data-driven and reflect real-world expertise. As such, CIS Benchmarks serve as a vital part of a robust cybersecurity program.

In general, CIS Benchmarks focus on secure technical configuration settings and should be used alongside essential cyber hygiene practices, such as monitoring and promptly patching vulnerabilities in operating systems, applications and libraries.

The CIS Google Chrome Benchmark defines security controls such as:

  • No domains can bypass scanning for dangerous resources such as phishing content and malware.
  • Strict verification of SSL/TLS certificates issued by websites.
  • Reducing Chrome’s overall attack surface by ensuring the latest updates are automatically applied periodically.
  • Chrome is configured to detect DNS interception which could potentially allow DNS hijacking.
  • Chrome and extensions cannot interact with other third party software.
  • Websites and browser extensions cannot abuse connections with media, the local file system or external devices such as Bluetooth, USB or media casting devices.
  • Only extensions from the Google Chrome Web Store can be installed.
  • All processes forked from the main Chrome process are stopped once the Chrome application has been closed.
  • SafeSites content filtering blocks links to adult content from search results.
  • Prevent importing insecure data such as auto-fill form data, default homepage or other configuration settings.
  • Ensuring that critical warnings cannot be suppressed.

Greenbone Is a CIS Consortium Member

As a member of the CIS consortium, Greenbone continues to enhance its CIS Benchmark scan configurations. All our CIS Benchmarks policies are aligned with CIS hardening guidelines and certified by CIS, ensuring maximum security for system audits. Also, Greenbone has added a new compliance view to the Greenbone Security Assistant (GSA) web-interface, streamlining the process for organizations seeking to remove security gaps from their infrastructure to prevent security breaches.

Summary

CIS Controls are critical for safeguarding systems and data by providing clear, actionable guidance on secure configurations. The CIS Google Chrome Benchmark is especially vital at the enterprise level, where browsers impact many forms of sensitive data. It’s exciting to announce that Greenbone is expanding the industry leading vulnerability detection capabilities with a new compliance scan: the CIS Google Chrome Benchmark v3.0.0 Level 1. With this certification, Greenbone continues to strengthen its position as a trusted ally in proactive cybersecurity. This latest feature reflects our dedication to advancing IT security and protecting against evolving cyber threats.