CVE-2025-12195 is an out-of-bounds write vulnerability classified under CWE-787 found in the command-line interface (CLI) of WatchGuard Fireware OS, a widely used network security operating system. The vulnerability arises when processing specially crafted IPSec configuration commands, allowing an authenticated user with privileged access to write outside the intended memory bounds. This memory corruption can lead to arbitrary code execution, enabling the attacker to take full control of the affected device. The affected versions span multiple major releases: 11.0 through 11.12.4+541730, 12.0 through 12.11.4, 12.5 through 12.5.13, and 2025.1 through 2025.1.2, indicating a broad impact across Fireware OS deployments. Exploitation requires no user interaction beyond authentication with high privileges, and no network access vector without such privileges is indicated. The CVSS 4.0 base score of 8.6 reflects the high impact on confidentiality, integrity, and availability, combined with low attack complexity and no need for user interaction. Although no public exploits are currently known, the vulnerability poses a significant risk to network security devices that serve as critical perimeter defenses. The lack of available patches at the time of disclosure necessitates immediate risk mitigation through access control and monitoring. The vulnerability’s presence in IPSec configuration commands is particularly concerning as IPSec is commonly used for secure VPN tunnels, meaning exploitation could undermine secure communications and network segmentation.

For European organizations, the exploitation of CVE-2025-12195 could lead to full compromise of WatchGuard Fireware OS devices, which often function as firewalls, VPN gateways, and intrusion prevention systems. This could result in unauthorized access to sensitive internal networks, interception or manipulation of encrypted traffic, disruption of secure communications, and potential lateral movement within corporate environments. Critical sectors such as finance, healthcare, government, and critical infrastructure relying on WatchGuard devices for network security could face operational outages, data breaches, and regulatory non-compliance. The ability to execute arbitrary code at a privileged level means attackers could disable security controls, install persistent malware, or exfiltrate confidential data. Given the central role of these devices in network defense, the impact extends beyond individual organizations to potentially affect supply chains and national cybersecurity postures. The absence of known exploits currently provides a window for mitigation, but the high severity score underscores the urgency of addressing this vulnerability to prevent future attacks.

1. Immediately restrict CLI access to WatchGuard Fireware OS devices to only trusted administrators using strong authentication methods such as multi-factor authentication (MFA). 2. Monitor logs and IPSec configuration changes for unusual or unauthorized activity that could indicate exploitation attempts. 3. Implement network segmentation to limit the exposure of Fireware OS management interfaces to trusted networks only. 4. Prepare for patch deployment by tracking vendor updates closely, and apply security patches as soon as they become available. 5. Conduct regular audits of privileged user accounts and remove or disable unnecessary accounts to reduce the attack surface. 6. Employ intrusion detection/prevention systems (IDS/IPS) to detect anomalous traffic patterns related to IPSec configuration commands. 7. Educate administrators on the risks of this vulnerability and enforce strict operational security policies around device management. 8. Consider temporary compensating controls such as disabling IPSec configuration changes via CLI if operationally feasible until patches are applied.