-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

===========================================================================
AA-2009.0099                  AUSCERT Advisory

                                 [OpenBSD]
                        OpenBSD: Denial of Service
                               17 April 2009
- ---------------------------------------------------------------------------

        AusCERT Advisory Summary
        ------------------------

Product:              OpenBSD
Operating System:     OpenBSD
Impact:               Denial of Service
Access:               Remote/Unauthenticated
Member content until: Friday, May 15 2009

OVERVIEW:

       A vulnerability has been identified in OpenBSD that can cause a
       kernel panic.


IMPACT:

       The vendor has provided the following information regarding this
       vulnerability:

       "When pf attempts to perform translation on a specially crafted IP 
       datagram, a null pointer dereference will occur, resulting in a 
       kernel panic. In certain configurations this may be triggered by a 
       remote attacker." [1,2,3]

       This vulnerability affects versions 4.3, 4.4, 4.5.


MITIGATION:

       The vulnerability as been corrected in -current. Soruce patches are
       available for 4.3 [4], 4.4 [5], 4.5 [6].


REFERENCES:

       [1] OpenBSD 4.3 errata
           http://www.openbsd.org/errata43.html

       [2] OpenBSD 4.4 errata
           http://www.openbsd.org/errata44.html

       [3] OpenBSD 4.5 errata
           http://www.openbsd.org/errata45.html

       [4] 013_pf.patch
           ftp://ftp.openbsd.org/pub/OpenBSD/patches/4.3/common/013_pf.patch

       [5] 013_pf.patch
           ftp://ftp.openbsd.org/pub/OpenBSD/patches/4.4/common/013_pf.patch
  
       [6] 002_pf.patch
           ftp://ftp.openbsd.org/pub/OpenBSD/patches/4.5/common/002_pf.patch

AusCERT has made every effort to ensure that the information contained
in this document is accurate.  However, the decision to use the information
described is the responsibility of each user or organisation. The decision to
follow or act on information or advice contained in this security bulletin is
the responsibility of each user or organisation, and should be considered in
accordance with your organisation's site policies and procedures. AusCERT
takes no responsibility for consequences which may arise from following or
acting on information or advice contained in this security bulletin.

If you believe that your computer system has been compromised or attacked in 
any way, we encourage you to let us know by completing the secure National IT 
Incident Reporting Form at:

        http://www.auscert.org.au/render.html?it=3192

===========================================================================
Australian Computer Emergency Response Team
The University of Queensland
Brisbane
Qld 4072

Internet Email: auscert@auscert.org.au
Facsimile:      (07) 3365 7031
Telephone:      (07) 3365 4417 (International: +61 7 3365 4417)
                AusCERT personnel answer during Queensland business hours
                which are GMT+10:00 (AEST).
                On call after hours for member emergencies only.
===========================================================================

-----BEGIN PGP SIGNATURE-----
Comment: http://www.auscert.org.au/render.html?it=1967

iD4DBQFJ6BKTNVH5XJJInbgRAqcoAJjg/ME2vCMQVMdthVG1NHyXwQCnAKCFMlYJ
1/RV5CEAid4/Kj65LWqjOw==
=65ak
-----END PGP SIGNATURE-----