CVE-2025-1547 is a stack-based buffer overflow vulnerability classified under CWE-121, found in WatchGuard Fireware OS's certificate request command interface. The flaw exists in the way the OS processes specially crafted CLI commands related to certificate requests, leading to a buffer overflow on the stack. This overflow can be exploited by an authenticated user with high privileges to execute arbitrary code, potentially allowing full control over the affected device. The vulnerability impacts Fireware OS versions from 12.0 through 12.5.12+701324 and 12.6 through 12.11.2. The CVSS v4.0 score is 7.5, indicating high severity, with an attack vector of network (remote), high attack complexity, requiring privileged authentication but no user interaction. The vulnerability affects confidentiality, integrity, and availability with high impact, and does not require scope change or user interaction. No known public exploits exist yet, but the potential for severe compromise of network security appliances is significant. WatchGuard Fireware OS is widely used in enterprise and government network security appliances, making this vulnerability critical for organizations relying on these devices for perimeter defense and secure communications.

For European organizations, this vulnerability poses a significant risk to network security infrastructure. Exploitation could lead to complete compromise of Fireware OS devices, allowing attackers to bypass firewall protections, intercept or manipulate network traffic, and disrupt availability of critical services. This is particularly concerning for sectors such as finance, government, healthcare, and critical infrastructure operators that rely heavily on WatchGuard devices for secure network perimeter defense. The ability to execute arbitrary code with high privileges could facilitate lateral movement within networks, data exfiltration, or deployment of ransomware. The lack of public exploits currently reduces immediate risk, but the high severity and privileged access requirement mean that insider threats or compromised administrative accounts could be leveraged. The impact extends to confidentiality, integrity, and availability of network communications and systems protected by affected devices.

Organizations should prioritize applying official patches from WatchGuard as soon as they become available. Until patches are released, restrict CLI access to trusted administrators only and enforce strong authentication and access controls to minimize the risk of privileged account compromise. Implement network segmentation to limit exposure of Fireware OS management interfaces to untrusted networks. Monitor logs and command usage for unusual or unauthorized certificate request commands or other suspicious CLI activity. Employ intrusion detection systems to detect anomalous behavior on Fireware OS devices. Regularly audit privileged accounts and credentials to reduce the risk of insider threats. Consider temporary compensating controls such as disabling certificate request functionality if feasible. Maintain up-to-date backups and incident response plans to quickly recover in case of exploitation.