[CAN-2005-1062] Administration protocol abuse allows local/remote password cracking

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        Secure Computer Group - University of A Coruna
                http://research.tic.udc.es/scg/

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       dotpi.com Information Technologies Research Labs
                     http://www.dotpi.com

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ID: #20050429-1
Document title: Administration protocol abuse allows
local/remote password cracking
Document revision: 1.0

Coordinated release date: 2005/04/29
Vendor Acknowledge date: 2005/02/25
Reported date: 2005/02/21

CVE Name: CAN-2005-1062

Other references: N/A

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Summary:

Impact: Local/remote password cracking

Rating/Severity: Medium
Recommendation: Update to latest version
Enforce network ACLs
Enforce password policies

Vendor: Kerio Technologies Inc.

Affected software:

          o Kerio WinRoute Firewall up to and including 6.0.10

          o Kerio Personal Firewall up to and including 4.1.2

          o Kerio MailServer up to and including 6.0.8

Updates/Patches: Yes (see below)

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General Information:

1. Executive summary:

   Kerio WinRoute Firewall, Kerio Personal Firewall and Kerio
   MailServer drive a local/remote administration protocol in order
   to manage the service.

   This protocol can be abused in order to remotely retrieve user
   credentials through a brute forcing technique. Passwords 1-5
   characters long could be obtained quickly. As such, Kerio considers
   them insecure and recommends enforcing password policies. The
   attack is not practically usable for passwords longer than 5
   characters. User logins must be previously known for this attack to
   be successful.

   The logging component of the software can loose up to 40% of the
   events when the attack is in place.

   In order solve this problem, system administrators should enforce
   network ACL security settings and user password policies. It is
   also highly recommended to verify this settings as part of the
   planning, installation, hardening and auditing processes.

   New versions of the software solve this and other minor problems
   so an upgrade is highly recommended.

2. Technical details:

   Technical details and proof of concept code were provided to
   vendor.

3. Risk Assessment factors:

   The attacker should have access to the administration ports:

   o TCP/UDP 44333 - Kerio WinRoute Firewall Administration

   o TCP/UDP 44334 - Kerio Personal Firewall Administration

   o TCP/UDP 44337 - Kerio MailServer Administration

   Network effective bandwidth between the system and the attacker is
   also an important speed and success factor.

   User logins must be previously known or previously brute forced
   for this attack to be successful.

   Special attention should be taken on environments on which NT,
   Active Directory or Open Directory integration is in place.
   GINA.DLL re-login delay features are bypassed and therefore the
   brute forcing procedure is considerably quicker.

   Local/Domain User Lock-out policies can help on contenting this
   attack. Despite that, an user login denial of service can emerge
   as a side effect.

   The most risky scenarios are the ones in which the server machine
   is shared among two or more interactive users/administrators or
   those situations where Kerio service management have been
   delegated to a third party.

   The weakeness on the logging facility can be a target on its own
   in order to hide any other attack that is being performed
   simultaneously.

   Special care should be taken on such environments and every step
   of the project: design, planning, deployment and management
   should consider this security issues.

   Privilege escalation, system and software tampering and the
   ability to alter service configuration are all real issues and
   all of them can be used as a second stage attack vector.

4. Solutions and recommendations:

   Upgrade to the latest versions:

   o Kerio Winroute Firewall 6.0.11 and above

   o Kerio Personal Firewall 4.1.3 and above

   o Kerio MailServer 6.0.9 and above

   As in any other case, follow, as much as possible, the Industry
   'Best Practices' on Planning, Deployment and Operation on this
   kind of services.

5. Common Vulnerabilities and Exposures (CVE) project:

   The Common Vulnerabilities and Exposures (CVE) project has
   assigned the name CAN-2005-1062 to this issue. This is a
   candidate for inclusion in the CVE list (http://cve.mitre.org),
   which standardizes names for security problems.

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Acknowledgements:

1. Special thanks to Vladimir Toncar and the whole Technical Team from
   Kerio Technologies (support at kerio.com) for their quick response
   and professional handling on this issue.

2. The whole Research Lab at dotpi.com and specially to Carlos Veira.

3. Secure Computer Group at University of A Coruna (scg at udc.es),
   and specially to Antonino Santos del Riego.

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Credits:

Javier Munoz (Secure Computer Group) is credited with this discovery.

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Related Links:

[1] Kerio Technologies Inc.
http://www.kerio.com/

[2] Kerio WinRoute Firewall Downloads & Updates
http://www.kerio.com/kwf_download.html

[3] Kerio Personal Firewall Downloads & Updates
http://www.kerio.com/kpf_download.html

[4] Kerio MailServer Downloads & Updates
http://www.kerio.com/kms_download.html

[5] Secure Computer Group. University of A Coruna
http://research.tic.udc.es/scg/

[6] Secure Computer Group. Updated advisory
http://research.tic.udc.es/scg/advisories/20050429-1.txt

[7] dotpi.com Information Technologies S.L.
http://www.dotpi.com/

[8] dotpi.com Research Labs
http://www.dotpi.com/research/

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Copyright (c) 2002-2005 Secure Computer Group. University of A Coruna
Copyright (c) 2004-2005 dotpi.com Information Technologies S.L.

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