Description

FreePBX is an open-source web-based graphical user interface (GUI) that manages Asterisk. Prior to versions 16.0.45 and 17.0.24 of the FreePBX framework, an authenticated local privilege escalation exists in the deprecated FreePBX startup script `amportal`. In the deprecated `amportal` utility, the lookup for the `freepbx_engine` file occurs in `/etc/asterisk/` directories. Typically, these are configured by FreePBX as writable by the **asterisk** user and any members of the **asterisk** group. This means that a member of the **asterisk** group can add their own `freepbx_engine` file in `/etc/asterisk/` and upon `amportal` executing, it would exec that file with root permissions (even though the file was created and placed by a non-root user). Version 16.0.45 and 17.0.24 contain a fix for the issue. Other mitigation strategies are also available. Confirm only trusted local OS system users are members of the `asterisk` group. Look for suspicious files in the `/etc/asterisk/` directory (via Admin -> Config Edit in the GUI, or via CLI). Double-check that `live_dangerously = no` is set (or unconfigured, as the default is **no**) in `/etc/asterisk/asterisk.conf` file. Eliminate any unsafe custom use of Asterisk dial plan applications and functions that potentially can manipulate the file system, e.g., System(), FILE(), etc.

CVSS Vector

Weaknesses (CWE)

Affected Products (2)

References (2)