Fortiadc CVE-2025-31104

The CVSS 3.1 vector (AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H) indicates moderate real-world exploitability: while the attack vector is network-based with low complexity, the requirement for high-level privileges (PR:H) significantly restricts the attacker pool to administrators or users with administrative credentials. The lack of user interaction required (UI:N) means exploitation is fully automated once access is obtained. The impact metrics (C:H/I:H/A:H) confirm complete system compromise. Without specific EPSS probability data or KEV status confirmation provided, the privilege requirement acts as a natural limiting factor—this is not a wormable vulnerability. However, in environments where administrative credentials are compromised, shared, or where insider threats exist, this becomes critical. The wide version range affected (6.1 through 7.6.1) suggests either a long-standing design flaw or recurring pattern of inadequate input validation across versions. This warrants prioritization in patching but should be contextualized as lower risk than network-exploitable vulnerabilities without privilege requirements.

An authenticated administrator at a financial institution discovers their FortiADC is running version 7.4.3. A disgruntled IT staff member with administrative credentials logs into the FortiADC management interface. Instead of making legitimate configuration changes, they craft a specially-formed HTTP POST request to a vulnerable endpoint (likely a configuration, diagnostic, or reporting feature), injecting shell commands such as ; cat /etc/passwd; or $(whoami) into a parameter. The FortiADC backend processes this request without proper input sanitization and executes the injected commands with root privileges. The attacker gains shell access to the underlying Linux system, allowing them to exfiltrate traffic data, modify security policies, install backdoors, or pivot to other network devices. Detection is hindered by the fact that the attack originates from a legitimate administrative session, making it appear as normal administrative activity in basic logs.