FreePBX is an open source IP PBX. Prior to versions 16.0.40 and 17.0.7, a critical remote code execution (RCE) vulnerability exists in the superfecta module due to unsafe inclusion of arbitrary PHP files, allowing authenticated attackers to execute arbitrary PHP code on the server with the privileges of the web server user. Authentication with a known username is required. The vulnerability is rooted in the options and save_options cases in the Superfecta module's AJAX handler. The code dynamically includes PHP files from the sources/ directory based on user-supplied input. This allows an attacker to execute arbitrary code when combined with arbitrary directory creation (e.g., via the backup module) and file uploads that reveal full paths (e.g., via the soundlang module). This issue has been patched in versions 16.0.40 and 17.0.7.