The code inside eval-stdin.php is deceptively simple. It was designed to facilitate internal testing by reading data from the standard input ( php://input ) and executing it directly using PHP’s eval() function. In essence, the script acts as a conduit: whatever raw data is sent to it, it will run as PHP code. The vulnerable snippet of code essentially looks like this:
The vulnerability exists in PHPUnit utility script eval-stdin.php . This script was designed to receive PHP code via standard input (stdin) and execute it using PHP's eval() function. The core security flaw is that this script was often deployed to production environments inside the vendor/ directory and left publicly accessible via the web server. Because the script does not verify who is sending the request, anyone can send HTTP POST data containing malicious PHP code to this file, forcing the server to execute it immediately. How the Exploit Works vendor phpunit phpunit src util php eval-stdin.php exploit
Output: uid=33(www-data) gid=33(www-data) groups=33(www-data) The code inside eval-stdin
A: No. This is an unauthenticated RCE vulnerability. An attacker does not need a username, password, or any prior access to the target website. The vulnerable snippet of code essentially looks like
: Multiple modules historically included vulnerable copies of PHPUnit within their own directories.