AudioCodes Fax Server and Auto-Attendant IVR appliances versions up to and including 2.6.23 configure the web document root at C:F2MAdminF2E with overly permissive file system permissions. Authenticated local users have modify rights on this directory, while the associated web server process runs as NT AUTHORITYSYSTEM. As a result, any local user can create or alter server-side scripts within the webroot and then trigger them via HTTP requests, causing arbitrary code to execute with SYSTEM privileges.
Weakness
During installation, installed file permissions are set to allow anyone to modify those files.
Potential Mitigations
- Compartmentalize the system to have “safe” areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.
- Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.
References