PHPUnit uses this file internally when running tests in isolated processes. Instead of saving temporary PHP files to disk, PHPUnit pipes test code directly into a subprocess. The subprocess invokes eval-stdin.php , which reads the incoming code from STDIN and executes it instantly via eval() .
. This allows the script to read the raw body of an HTTP POST request and execute it as PHP code. Root Cause : The vulnerability is triggered when the PHPUnit uses this file internally when running tests
The flaw centers on a utility script called eval-stdin.php located in the /vendor/phpunit/phpunit/src/Util/PHP/ directory. This file was designed to read PHP code from a standard input (STDIN) stream and execute it using PHP’s eval() function. This file was designed to read PHP code
Web crawlers, those mindless digital insects, began to map the directory. They didn’t see a testing utility; they saw a "Remote Code Execution" vulnerability. They indexed the path, pinning it to the public board of the internet like a "Kick Me" sign on a giant’s back. They indexed the path