Once a web shell is uploaded, the attacker has a "backdoor" into your server, allowing them to steal data, delete files, or use your server to launch attacks on others. Why is it showing up as an "Index of"?
If your vendor folder is visible this way, it’s a double failure: index of vendor phpunit phpunit src util php evalstdinphp
Run composer install --no-dev to ensure development dependencies are removed. Once a web shell is uploaded, the attacker
This exposure is tracked under . It is one of the most frequently scanned-for vulnerabilities on the internet because it is incredibly easy to exploit. How the Attack Works: This exposure is tracked under
Once found, the attacker sends a POST request to eval-stdin.php .
The file eval-stdin.php was originally part of the PHPUnit framework. Its purpose was to allow the framework to execute PHP code passed via the standard input (stdin). While useful for testing environments, it was never intended to be accessible from a public-facing web directory.
Attackers use search engines (Google Dorks) or automated scripts to find "Index of" pages containing the vendor/phpunit path.
