Critical WatchGuard Fireware Vulnerability Actively Exploited
A critical out-of-bounds write vulnerability, tracked as CVE-2025-9242, has been discovered in WatchGuard Fireware OS, affecting versions 11.10.2 through 11.12.4_Update1, 12.0 through 12.11.3, and 2025.1. This flaw allows remote, unauthenticated attackers to execute arbitrary code on vulnerable Firebox firewall devices by exploiting a missing length check during the IKE handshake process. The U.S. Cybersecurity and Infrastructure Security Agency (CISA) has added this vulnerability to its Known Exploited Vulnerabilities (KEV) catalog following evidence of active exploitation, and has mandated that Federal Civilian Executive Branch (FCEB) agencies apply patches by December 3, 2025. As of mid-November, over 54,000 Firebox devices remain exposed globally, with the highest concentrations in the U.S., Italy, the U.K., Germany, and Canada.
WatchGuard released patches for the vulnerability on September 17, 2025, but only confirmed active exploitation in late October. CISA has emphasized the significant risk posed by this flaw, urging all organizations—not just federal agencies—to prioritize patching due to the attractiveness of firewall devices as targets for threat actors. The vulnerability's exploitation path allows attackers to bypass authentication, as the vulnerable code is executed before certificate validation. Organizations unable to apply mitigations are advised to discontinue use of affected products to prevent compromise.
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How this story unfolded
4 events from the most recent confirmed update back to the earliest known activity.
Researchers report more than 54,000 WatchGuard Fireboxes remain exposed
Reporting on the vulnerability noted that over 54,300 WatchGuard Firebox devices worldwide were still vulnerable, with the largest concentration in the United States. The scale and methods of exploitation were not yet publicly clear.
CISA adds CVE-2025-9242 to the KEV catalog over active exploitation
CISA added WatchGuard Fireware OS vulnerability CVE-2025-9242 to its Known Exploited Vulnerabilities catalog after evidence showed it was being actively exploited in attacks. Federal Civilian Executive Branch agencies were directed to remediate the issue by December 3, 2025.
WatchGuard releases patches for CVE-2025-9242
WatchGuard released security updates to fix CVE-2025-9242 in Fireware OS. The flaw was considered highly critical because it could be exploited pre-authentication on exposed Firebox devices.
watchTowr Labs discloses critical WatchGuard Fireware flaw CVE-2025-9242
watchTowr Labs disclosed CVE-2025-9242, a critical out-of-bounds write in the iked process of WatchGuard Fireware OS. The bug stems from a missing length check during the IKE handshake and allows remote unauthenticated code execution before login.
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CISA Flags Critical WatchGuard Fireware Flaw Exposing 54,000 Fireboxes to No-Login Attacks
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Open sourceCISA warns of WatchGuard firewall flaw exploited in attacks
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Open sourceAttacks involving critical WatchGuard Firebox bug ongoing, CISA warns
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Active Exploitation of Critical WatchGuard Firebox Vulnerabilities
WatchGuard has confirmed that its Firebox firewall devices are being actively targeted due to a critical remote code execution vulnerability, CVE-2025-32978, which allows unauthenticated attackers to execute arbitrary commands remotely. The flaw resides in the Fireware OS Internet Key Exchange (IKE) service and can be exploited if the device is accessible over the internet, potentially giving attackers full control of the firewall. WatchGuard has released emergency patches and indicators of compromise, urging customers to update their firmware immediately or apply temporary workarounds if patching is not possible. The vulnerability affects configurations involving mobile user VPN with IKEv2 and branch office VPNs using IKEv2, even if some configurations have been deleted but others remain. In response to evidence of active exploitation, CISA has added a WatchGuard Firebox vulnerability to its Known Exploited Vulnerabilities (KEV) Catalog, highlighting the significant risk such flaws pose to federal and enterprise networks. CISA's directive requires federal agencies to remediate these vulnerabilities by a set deadline and strongly encourages all organizations to prioritize patching to reduce exposure to cyberattacks. The inclusion in the KEV Catalog underscores the urgency for organizations to address these vulnerabilities as part of their ongoing vulnerability management practices.
Jun 29, 2026
Critical Remote Code Execution Vulnerability in WatchGuard Fireware OS VPN
A critical vulnerability, tracked as CVE-2025-9242, has been discovered in WatchGuard's Fireware OS, affecting a wide range of Firebox network security appliances. This flaw is an out-of-bounds write in the 'iked' process, which is responsible for handling IKEv2 VPN negotiations. The vulnerability allows remote attackers to execute arbitrary code on affected devices without authentication, posing a severe risk to organizations relying on these appliances for network security. The issue specifically impacts devices configured with mobile user VPNs or branch office VPNs using IKEv2 with dynamic gateway peers. Security researchers have demonstrated that attackers can exploit this bug by sending specially crafted IKEv2 packets during the IKE_SA_AUTH phase, triggering a buffer overflow in the ike2_ProcessPayload_CERT function. Once exploited, attackers can gain control of the instruction pointer, establish Python interactive shells over TCP, and escalate to a full Linux shell by remounting filesystems and deploying BusyBox binaries. The vulnerability has been assigned a CVSS score of 9.3, underscoring its critical nature. According to scans by The Shadowserver Foundation, nearly 76,000 Firebox appliances remain exposed and vulnerable on the public internet, with the highest concentrations in the United States, Germany, Italy, the United Kingdom, Canada, and France. Affected Fireware OS versions include 11.10.2 through 11.12.4_Update1, the entire 12.0 series up to 12.11.3, and the 2025.1 release, impacting both older and newer Firebox models. WatchGuard has released patches in versions 12.3.1_Update3, 12.5.13, 12.11.4, and 2025.1.1 to address the vulnerability. Devices running version 11.x are no longer supported and will not receive security updates, prompting the vendor to recommend upgrading to a supported version. For appliances configured only with Branch Office VPNs to static gateway peers, WatchGuard has provided documentation for securing connections as a temporary workaround. The vulnerability transforms trusted security appliances into potential entry points for attackers, threatening the integrity of network defenses. Organizations are urged to assess their Firebox deployments, prioritize patching, and review VPN configurations to mitigate the risk. The widespread exposure of vulnerable devices highlights the urgency of remediation efforts. WatchGuard's disclosure and the subsequent public scanning have brought significant attention to the issue, emphasizing the importance of timely patch management in network security infrastructure. Failure to address this vulnerability could result in unauthorized access, lateral movement, and compromise of sensitive internal networks. The incident serves as a stark reminder of the risks posed by critical flaws in security appliances and the need for continuous monitoring and rapid response.
Jun 29, 2026
Critical Remote Code Execution Vulnerability in WatchGuard Fireware OS VPN (CVE-2025-9242)
A critical security vulnerability, tracked as CVE-2025-9242, was discovered in WatchGuard Fireware OS, which powers WatchGuard’s Firebox network security appliances. This flaw is an out-of-bounds write vulnerability in the iked process, specifically within the function 'ike2_ProcessPayload_CERT' in the file 'src/ike/iked/v2/ike2_payload_cert.c'. The vulnerability arises due to a missing length check on the identification buffer, allowing a remote, unauthenticated attacker to trigger a stack-based buffer overflow. Exploitation of this flaw enables arbitrary code execution during the IKE_SA_AUTH phase of the IKEv2 handshake, which is used to establish VPN tunnels. The vulnerability affects both mobile user VPNs and branch office VPNs configured with dynamic gateway peers, making it a significant risk for organizations relying on these features. Fireware OS versions 11.10.2 up to and including 11.12.4_Update1, 12.0 up to and including 12.11.3, and 2025.1 are impacted, with fixes released in 2025.1.1, 12.11.4, 12.3.1_Update3 (FIPS-certified), and 12.5.13 for specific models. The 11.x branch has reached end-of-life and is no longer supported. Security researchers, including McCaulay Hudson of watchTowr Labs, highlighted that the vulnerability is particularly attractive to ransomware groups due to its remote, unauthenticated nature and the fact that it targets internet-exposed perimeter appliances. WatchGuard’s Fireware OS is widely deployed, protecting over 250,000 small and midsize enterprises and more than 10 million endpoints globally, amplifying the potential impact of this vulnerability. The flaw was disclosed and patched following responsible disclosure, with WatchGuard issuing an advisory and urging customers to update affected devices immediately. The vulnerability underscores the ongoing risk posed by classic buffer overflow issues, even in modern enterprise-grade security appliances. Researchers were able to reproduce the exploit, demonstrating the ease with which attackers could compromise vulnerable systems. The lack of mainstream exploit mitigations in the affected code path further increases the risk of successful exploitation. Organizations using WatchGuard Fireware OS are advised to review their VPN configurations, apply the latest patches, and consider additional monitoring for signs of exploitation. The incident highlights the importance of timely patch management and the persistent threat posed by memory safety vulnerabilities in critical infrastructure.
Jun 29, 2026