CVE-2023-23328

Vulnerability

A file upload vulnerability exists in AvantFAX 3.3.7 within FileUpload.php. An authenticated user can bypass PHP file type validation by uploading a specially crafted PHP file. This allows the attacker to place arbitrary PHP code on the server, which can then be executed. The vulnerability affects AvantFAX version 3.3.7 and possibly earlier releases [1].

Exploitation

An attacker must have valid authentication credentials for the AvantFAX application. The attacker then uploads a PHP file that evades the file type checks implemented in FileUpload.php. No additional user interaction or special network position is required beyond being an authenticated user [1].

Impact

Successful exploitation results in remote code execution (RCE) on the underlying server. The attacker can execute arbitrary PHP code with the privileges of the web server, potentially leading to full compromise of the AvantFAX installation and access to sensitive data [1].

Mitigation

The vendor released an updated version of AvantFAX on January 10, 2023, which remediates this vulnerability. Users should upgrade to the latest version. No workarounds are documented in the available references [1].