CVE-2025-55211 is a medium-severity OS command injection vulnerability affecting the FreePBX open-source web-based graphical user interface, specifically within its security-reporting component. The vulnerability exists in versions from 17.0.19.11 up to but not including 17.0.21. Authenticated users with access to the Administrator Control Panel (ACP) can exploit this flaw by maliciously altering the language settings of the framework module. This improper neutralization of special elements (CWE-78) allows attackers to inject and execute arbitrary shell commands on the underlying operating system. The vulnerability does not require user interaction beyond authentication and can be exploited remotely over the network (AV:N). The attack complexity is low (AC:L), and no additional privileges beyond administrator-level access are needed (PR:L). The vulnerability impacts confidentiality, integrity, and availability at a high level, as arbitrary command execution can lead to data breaches, system compromise, or denial of service. The issue has been fixed in version 17.0.21 of FreePBX. No known exploits are currently reported in the wild, but the presence of this vulnerability in a widely deployed telephony management system makes it a significant risk if left unpatched.

For European organizations, the impact of CVE-2025-55211 can be substantial, particularly for those relying on FreePBX for telephony infrastructure management. Successful exploitation could lead to unauthorized command execution on critical communication servers, potentially resulting in interception or disruption of voice communications, data leakage, or full system compromise. This could affect business continuity, regulatory compliance (e.g., GDPR), and customer trust. Given that FreePBX is often integrated into enterprise telephony and call center environments, attackers could leverage this vulnerability to pivot into broader network environments. The medium CVSS score reflects the requirement for administrator-level authentication, which somewhat limits exposure but does not eliminate risk, especially in environments with weak credential management or insider threats.

1. Immediate upgrade to FreePBX version 17.0.21 or later to apply the official patch addressing this vulnerability. 2. Restrict and monitor administrator access to the ACP, enforcing strong authentication mechanisms such as multi-factor authentication (MFA) to reduce the risk of credential compromise. 3. Implement network segmentation to isolate FreePBX servers from general user networks and limit exposure to trusted administrators only. 4. Regularly audit and monitor logs for unusual changes to language settings or other configuration parameters indicative of exploitation attempts. 5. Employ application-layer firewalls or intrusion detection/prevention systems (IDS/IPS) configured to detect anomalous command injection patterns targeting FreePBX. 6. Conduct periodic security assessments and penetration testing focused on telephony infrastructure to identify and remediate similar vulnerabilities proactively.