A critical security vulnerability, identified as CVE-2025-25257, has been discovered in Fortinet’s FortiWeb Fabric Connector, allowing unauthenticated attackers to execute remote code on affected systems. This flaw poses a significant threat to organizations utilizing Fortinet’s web application firewall solutions.
Key Takeaways:
1. Unauthenticated SQL Injection Vulnerability: The FortiWeb Fabric Connector contains an unauthenticated SQL injection flaw (CVE-2025-25257) that enables remote code execution.
2. Affected Versions and Patching: The vulnerability impacts FortiWeb versions 7.0.0 through 7.0.10, 7.2.0 through 7.2.10, 7.4.0 through 7.4.7, and 7.6.0 through 7.6.3. Fortinet has released patches requiring upgrades to versions 7.0.11, 7.2.11, 7.4.8, and 7.6.4, respectively.
3. Potential Impact: Attackers can bypass authentication mechanisms, gain root access, and execute arbitrary code by writing malicious files to the system.
4. Mitigation Measures: Organizations are advised to apply the provided patches promptly, restrict API access, and monitor systems for suspicious activity to prevent potential compromises.
Technical Details:
The vulnerability originates from an unauthenticated SQL injection flaw within the `get_fabric_user_by_token` function of the FortiWeb Fabric Connector. This function processes authentication tokens from external Fortinet devices integrating with FortiWeb APIs. The flaw arises due to improper construction of SQL queries, where user-controlled input is directly inserted without adequate sanitization or parameterization.
Specifically, the vulnerable code utilizes the `snprintf` function to build queries like `select id from fabric_user.user_table where token=’%s’`, with the token value derived directly from HTTP Authorization headers. This classic SQL injection vulnerability can be exploited through specially crafted Bearer tokens in API requests to endpoints such as `/api/fabric/device/status`.
Exploitation Methodology:
Exploitation requires understanding the input constraints imposed by the `sscanf` function, which stops parsing at the first space character and limits input to 128 characters. Attackers can bypass these restrictions using MySQL comment syntax (`//`) to replace spaces and carefully crafted payloads that fit within the character limit.
Researchers demonstrated that attackers can bypass authentication entirely using simple payloads like `AAAAAA’or’1’=’1`, causing the SQL query to return successful authentication for any request. More sophisticated attacks leverage MySQL’s `INTO OUTFILE` statement to write arbitrary files to the filesystem.
Elevated Risk Due to Misconfiguration:
The vulnerability becomes particularly dangerous due to FortiWeb’s configuration, where the MySQL process runs with root privileges rather than the typical restricted `mysql` user account. This misconfiguration allows attackers to write files anywhere on the system with root permissions.
Researchers successfully escalated the SQL injection to remote code execution by exploiting Python’s site-packages mechanism. They demonstrated writing malicious `.pth` files containing Python code that execute automatically when the system’s CGI scripts run Python processes.
Mitigation Recommendations:
1. Immediate Patching: Organizations should upgrade FortiWeb to the patched versions: 7.0.11, 7.2.11, 7.4.8, or 7.6.4, depending on their current deployment.
2. Restrict API Access: Limit access to the FortiWeb API to trusted networks and authenticated users to reduce the attack surface.
3. Monitor System Activity: Implement monitoring for unusual activities, such as unexpected file creations or modifications, which may indicate exploitation attempts.
4. Review System Configurations: Ensure that services like MySQL run with the least privileges necessary to perform their functions, minimizing potential impact in case of exploitation.
Conclusion:
The discovery and exploitation of CVE-2025-25257 in Fortinet’s FortiWeb Fabric Connector underscore the critical importance of timely vulnerability management and system configuration reviews. Organizations must act swiftly to apply patches, restrict access, and monitor their systems to mitigate the risks associated with this vulnerability.
