WordPress (CMS) WebApp-Builder File Upload RCE

There is an arbitrary file upload vulnerability in the WordPress plugin WebApp-builder. The vulnerability is in the images.php file; there are no authentication checks or sanitization against the type of file being uploaded. A remote unauthenticated attacker can send a request to images.php uploading a file with executable code. This could lead to a complete compromise of the server.

Exploitation

Stages

1. The remote unauthenticated attacker sends a request to images.php uploading a file to the server.
2. The server responds successfully with the location of the file.

Prerequisites

The attacker must be able to send crafted packets to the target system.

Alert Logic Coverage

Alert Logic® has evaluated its customer base for exposure to the exploit and has developed signatures for mitigating the threat depending on the security service in place.

The Network-Based Intrusion Detection System (IDS) has been updated with the new signatures for this exploit when detected via Alert Logic Threat Manager™. If this signature is detected, an incident is generated in the Alert Logic console.

Recommendations for Mitigation

Upgrade to a non-vulnerable version to mitigate this vulnerability.