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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2006.0245 -- [NetBSD] bridge memory disclosure 31 March 2006 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: bridge(4) (network bridge device) Publisher: NetBSD Operating System: NetBSD Impact: Access Privileged Data Access: Existing Account Original Bulletin: ftp://ftp.netbsd.org/pub/NetBSD/security/advisories/NetBSD-SA2006-005.txt.asc - --------------------------BEGIN INCLUDED TEXT-------------------- - -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 NetBSD Security Advisory 2006-005 ================================= Topic: bridge memory disclosure Version: NetBSD-current: source prior to January 17, 2006 NetBSD 3.0: affected NetBSD 2.1: affected NetBSD 2.0.*: affected NetBSD 2.0: affected NetBSD 1.6.*: affected NetBSD 1.6: affected Severity: Kernel sensitive information can be disclosed Fixed: NetBSD-current: January 17, 2006 NetBSD-3-0 branch: February 12, 2006 (3.0.1 will include the fix) NetBSD-3 branch: February 12, 2006 NetBSD-2-1 branch: February 12, 2006 (2.1.1 will include the fix) NetBSD-2-0 branch: February 12, 2006 (2.0.4 will include the fix) NetBSD-2 branch: February 12, 2006 Abstract ======== An information disclosure issue exists in if_bridge(4) code. Technical Details ================= The bridge(4) ioctl(2) calls did not zero out the stack memory used to temporarily store the results of the ioctl(2) requests before copying them back to the requesting process. Thus portions of the kernel stack memory could be exposed to the calling process. The impact of this is minor since: 1. the number of bytes exposed is small 2. the location and therefore the contents cannot be controlled by the calling process and 3. the buffer is partially overwritten by the results Solutions and Workarounds ========================= For all NetBSD versions, you need to obtain fixed kernel sources, rebuild and install the new kernel, and reboot the system. The fixed source may be obtained from the NetBSD CVS repository. The following instructions briefly summarise how to upgrade your kernel. In these instructions, replace: ARCH with your architecture (from uname -m), and KERNCONF with the name of your kernel configuration file. To update from CVS, re-build, and re-install the kernel: # cd src # cvs update -d -P sys/net/if_bridge.c # ./build.sh kernel=KERNCONF # mv /netbsd /netbsd.old # cp sys/arch/ARCH/compile/obj/KERNCONF/netbsd /netbsd # shutdown -r now For more information on how to do this, see: http://www.NetBSD.org/guide/en/chap-kernel.html Thanks To ========= Xin LI for notification and the initial fixes. Christos Zoulas for implementing the fixes. Revision History ================ 2006-03-29 Initial release More Information ================ Advisories may be updated as new information becomes available. The most recent version of this advisory (PGP signed) can be found at ftp://ftp.NetBSD.org/pub/NetBSD/security/advisories/NetBSD-SA2006-005.txt.asc Information about NetBSD and NetBSD security can be found at http://www.NetBSD.org/ and http://www.NetBSD.org/Security/. Copyright 2006, The NetBSD Foundation, Inc. All Rights Reserved. Redistribution permitted only in full, unmodified form. $NetBSD: NetBSD-SA2006-005.txt,v 1.8 2006/03/29 11:14:28 adrianp Exp $ - -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2.2 (NetBSD) iQCVAwUBRCsC8z5Ru2/4N2IFAQI7LwP6A2xNHvoHx92Md1aBBcQ9s46KlbaemaYM UqmxUz6nlgYSvHq6/DYdFvNxxf2J/2dXNmhkSPdr5eHqXQ+uXIa0nt0WEmR6tVYY JlrK/HUOkaIQulokGtS3h1fpqgT0UFI4ZkbVd2BMU3zkV+DvfdoVh2+RqgkijpfJ 5DfSETl8gcQ= =obSz - -----END PGP SIGNATURE----- - --------------------------END INCLUDED TEXT-------------------- You have received this e-mail bulletin as a result of your organisation's registration with AusCERT. The mailing list you are subscribed to is maintained within your organisation, so if you do not wish to continue receiving these bulletins you should contact your local IT manager. If you do not know who that is, please send an email to auscert@auscert.org.au and we will forward your request to the appropriate person. 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If you have any questions or need further information, please contact them directly. Previous advisories and external security bulletins can be retrieved from: http://www.auscert.org.au/render.html?cid=1980 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 iQCVAwUBRCzAsih9+71yA2DNAQIZSgP8DdJXBf/CnOU+gQ4OFQhgMqLZfEPYDahp HbguL9qqOAC1XGT23J4++KqSeTXlPRa7360BXTL4wUqbAr95m12lPuyw5KnVZe+A VLoox40Pu0EH8aLbtwBjiMcgLKWIWDGsC+HXPyEzR9Sk8DvnC+GmNbw+/ojctYo8 nVyuxls1h8c= =Gh4T -----END PGP SIGNATURE-----