CVE-2025-1547 is a stack-based buffer overflow vulnerability classified under CWE-121, found in the certificate request command of WatchGuard Fireware OS. This vulnerability affects multiple versions of Fireware OS, specifically from 12.0 through 12.5.12+701324 and 12.6 through 12.11.2. The flaw allows an authenticated user with high privileges to send specially crafted CLI commands that overflow a stack buffer, enabling arbitrary code execution within the context of the Fireware OS process. The vulnerability does not require user interaction but does require privileged authentication, limiting the attack surface to users with elevated access. The CVSS 4.0 score is 7.5 (high), reflecting network attack vector with high impact on confidentiality, integrity, and availability, but with high attack complexity. No public exploits or active exploitation have been reported yet. The vulnerability could be leveraged to compromise firewall devices, potentially allowing attackers to manipulate firewall rules, intercept or redirect traffic, or disrupt network security controls. Given Fireware OS’s role in perimeter defense, successful exploitation could lead to significant network compromise.

For European organizations, the impact of CVE-2025-1547 could be severe, especially for those relying on WatchGuard Fireware OS for network security and perimeter defense. Exploitation could lead to full compromise of firewall devices, undermining confidentiality by exposing sensitive traffic, integrity by altering firewall policies, and availability by causing device crashes or denial of service. Critical sectors such as finance, healthcare, government, and telecommunications could face operational disruptions and data breaches. The requirement for privileged authentication reduces the risk from external attackers but raises concerns about insider threats or compromised administrative credentials. The absence of known exploits currently provides a window for proactive mitigation. However, once exploited, the consequences could include lateral movement within networks, data exfiltration, and disruption of critical services.

Organizations should immediately audit and restrict privileged CLI access to trusted administrators only, employing strong authentication mechanisms such as multi-factor authentication. Network segmentation should isolate management interfaces to limit exposure. Continuous monitoring and logging of CLI commands can help detect anomalous or unauthorized activity indicative of exploitation attempts. Since no patches are currently linked, organizations should engage with WatchGuard support for updates or workarounds. Applying principle of least privilege to administrative accounts and rotating credentials regularly will reduce risk. Additionally, implementing intrusion detection systems that can identify buffer overflow attempts or unusual command patterns on Fireware OS devices can provide early warning. Preparing incident response plans specific to firewall compromise scenarios is also advised.