PHPUnit eval-stdin.php Unauthenticated RCE

A remote code execution (RCE) vulnerability exists in the eval-stdin.php script used in the PHPUnit software package. This vulnerability is present in versions before 4.8.28 and in 5.x before 5.6.3. An attacker is able to inject PHP payloads via crafted requests, resulting in the ability to run arbitrary commands on the target host. No authentication is required for successful exploitation of this vulnerability.

Exploitation

Stages

1. The attacker sends an HTTP POST request to eval-stdin.php with a malicious PHP payload contained in the POST body.
2. The injected payload is passed to an eval function within eval-stdin.php and subsequently evaluated by the target host. The output is returned to the attacker.

Prerequisites

You will need the PHPUnit before 4.8.28 and 5.x before 5.6.3.

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.

Detection of this threat is provided via Alert Logic ActiveWatch for Web Security Manager service. Depending on your deployment of Web Security Manager, you will receive an incident (for out-of-band deployment) or the threat will be actively blocked and rejected (for the inline Web Security Manager Premier deployment) if an exploit attempt is observed.

Recommendations for Mitigation

Upgrade your software to the latest non-vulnerable version.