CyberGhost 6.5.0.3180 for Windows suffers from a SYSTEM privilege escalation vulnerability through the CG6Service service. This service establishes a NetNamedPipe endpoint that allows arbitrary installed applications to connect and call publicly exposed methods. The ConnectToVpnServer method accepts a connectionParams argument that provides attacker control of the OpenVPN command line. An attacker can specify a dynamic library plugin that should run for every new VPN connection attempt. This plugin will execute code in the context of the SYSTEM user.
Weakness
The product specifies permissions for a security-critical resource in a way that allows that resource to be read or modified by unintended actors.
Affected Software
| Name |
Vendor |
Start Version |
End Version |
| Cyberghost |
Cyberghostvpn |
6.5.0.3180 |
6.5.0.3180 |
Potential Mitigations
- Run the code in a “jail” or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict which files can be accessed in a particular directory or which commands can be executed by the software.
- OS-level examples include the Unix chroot jail, AppArmor, and SELinux. In general, managed code may provide some protection. For example, java.io.FilePermission in the Java SecurityManager allows the software to specify restrictions on file operations.
- This may not be a feasible solution, and it only limits the impact to the operating system; the rest of the application may still be subject to compromise.
- Be careful to avoid CWE-243 and other weaknesses related to jails.
References