CVE-2025-6947 is a medium-severity vulnerability classified under CWE-79, which pertains to improper neutralization of input during web page generation, commonly known as Cross-site Scripting (XSS). This specific vulnerability affects WatchGuard Fireware OS versions from 12.0 through 12.11.2. The flaw exists in the SIP Proxy module of the Fireware OS, allowing an authenticated administrator with a local management session on the Firebox device to inject and store malicious scripts. These scripts could then be executed in the context of the administrator's browser when viewing affected pages, potentially leading to session hijacking, unauthorized actions, or disclosure of sensitive information. The vulnerability requires an authenticated administrator session, meaning remote unauthenticated attackers cannot exploit it directly. The CVSS 4.0 base score is 4.8, reflecting a medium severity with network attack vector but requiring high privileges and user interaction. No known exploits are reported in the wild as of the publication date. The vulnerability is limited in scope to locally managed Firebox devices running the specified Fireware OS versions and does not affect unauthenticated users or remote management interfaces without authentication. The absence of a patch link suggests that remediation may require vendor updates or configuration changes once available.

For European organizations, this vulnerability poses a moderate risk primarily to network security infrastructure relying on WatchGuard Firebox devices running vulnerable Fireware OS versions. Successful exploitation could allow malicious insiders or compromised administrators to execute arbitrary scripts within the management interface, potentially leading to unauthorized configuration changes, disclosure of sensitive network information, or lateral movement within the network. Given that Firebox devices are often deployed as perimeter firewalls or VPN gateways, compromise could undermine network defenses and confidentiality. However, the requirement for authenticated administrator access limits the threat to scenarios involving insider threats or credential compromise. Organizations with strict access controls and monitoring of administrative sessions will be less impacted. Nonetheless, sectors with critical infrastructure or sensitive data in Europe, such as finance, healthcare, and government, should consider this vulnerability significant due to the potential for disruption or data leakage if exploited.

European organizations should implement the following specific mitigations: 1) Restrict administrative access to Firebox devices strictly to trusted personnel and enforce strong multi-factor authentication to reduce the risk of credential compromise. 2) Monitor and audit all administrative sessions for unusual activity to detect potential exploitation attempts early. 3) Isolate management interfaces from general network access by using dedicated management VLANs or out-of-band management networks to prevent unauthorized access. 4) Apply the latest Fireware OS updates from WatchGuard as soon as patches addressing this vulnerability become available. 5) Employ web application firewalls or intrusion detection systems capable of detecting anomalous script injections in administrative interfaces. 6) Conduct regular security training for administrators to recognize phishing or social engineering attempts that could lead to credential theft. 7) If immediate patching is not possible, consider disabling or limiting the SIP Proxy module functionality if it is not critical to operations, to reduce the attack surface.