WordPress Synoptic Theme Avatar Upload Arbitrary File Upload

The default installation of the Synoptic Premium WordPress Theme's Avatar upload has an empty file extension whitelist, allowing the upload of arbitrary files.

Exploitation

Stages

1. The attacker sends an HTTP POST request with executable PHP file to the vulnerable Synoptic WordPress Theme’s Avatarupload.
2. The server stores the executable PHP file and responds with an HTTP 200 OK and JSON response message to indicate success.

Prerequisites

The attacker is able to access the vulnerable upload functionality directly and without authentication.

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.