CVE-2025-9242 is an out-of-bounds write vulnerability classified under CWE-787 found in WatchGuard Fireware OS, specifically impacting VPN functionalities using IKEv2 with dynamic gateway peer configurations. The vulnerability affects multiple versions of Fireware OS, including 11.10.2 up to 11.12.4_Update1, 12.0 up to 12.11.3, and 2025.1. The flaw arises from improper bounds checking during processing of VPN connections, allowing an attacker to write data outside the intended memory buffer. This memory corruption can be exploited remotely without authentication or user interaction, enabling arbitrary code execution with high impact on system confidentiality, integrity, and availability. The vulnerability is network exploitable (AV:N), requires no privileges (PR:N), no user interaction (UI:N), and has high impact on all security objectives (VC:H, VI:H, VA:H). The affected components are the Mobile User VPN and Branch Office VPN using IKEv2 with dynamic gateway peers, which are common configurations in enterprise VPN deployments. Although no known exploits have been reported in the wild, the critical severity and ease of exploitation make this a significant threat. The lack of available patches at the time of disclosure necessitates immediate attention to mitigation strategies to protect affected systems.

For European organizations, the impact of CVE-2025-9242 is substantial due to the widespread use of WatchGuard Fireware OS in enterprise VPN solutions. Successful exploitation could lead to full compromise of VPN gateways, allowing attackers to execute arbitrary code remotely, potentially leading to unauthorized access to internal networks, data exfiltration, disruption of VPN services, and lateral movement within corporate environments. This risk is heightened for organizations relying on dynamic gateway peer configurations in their VPN setups. Critical infrastructure, financial institutions, government agencies, and large enterprises in Europe that depend on secure remote access could face severe operational and reputational damage. The vulnerability undermines the confidentiality, integrity, and availability of VPN services, which are essential for secure communications, especially in the context of increased remote work and digital transformation initiatives across Europe.

Given the absence of published patches at the time of this analysis, European organizations should implement immediate mitigations including: 1) Reviewing and temporarily disabling dynamic gateway peer configurations in IKEv2 VPN setups if feasible. 2) Restricting VPN access to trusted IP ranges and enforcing strict network segmentation to limit exposure of vulnerable Fireware OS devices. 3) Monitoring network traffic for anomalous activity indicative of exploitation attempts targeting VPN services. 4) Applying strict firewall rules to limit inbound VPN connection attempts to known and authorized sources. 5) Preparing for rapid deployment of patches once released by WatchGuard by establishing a vulnerability management process prioritizing Fireware OS devices. 6) Conducting thorough audits of VPN configurations and logs to detect potential exploitation signs. 7) Engaging with WatchGuard support for any available workarounds or interim fixes. These targeted actions go beyond generic advice by focusing on the specific vulnerable configurations and attack vectors associated with this vulnerability.