-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 NetBSD Security Advisory 2008-015 ================================= Topic: ICMPv6 Packet Too Big messages Version: NetBSD-current: affected NetBSD 4.0.*: not affected NetBSD 4.0: affected NetBSD 3.1.*: affected NetBSD 3.1: affected NetBSD 3.0.*: affected NetBSD 3.0: affected Severity: Denial of service Fixed: NetBSD-current: October 03, 2008 NetBSD-4-0 branch: October 03, 2008 (4.0.1 includes the fix) NetBSD-4 branch: October 03, 2008 (4.1 will include the fix) NetBSD-3-1 branch: October 03, 2008 (3.1.2 will include the fix) NetBSD-3-0 branch: October 03, 2008 (3.0.4 will include the fix) NetBSD-3 branch: October 03, 2008 (3.2 will include the fix) Abstract ======== An error may occur while processing ICMPv6 'Packet Too Big' (RFC 2463) messages which may result in a denial of service (system panic). This vulnerability has been assigned CVE-2008-3530. Technical Details ================= An error can occur when processing the proposed MTU of an ICMPv6 'Packet Too Big' message. Solutions and Workarounds ========================= Only kernels compiled with the following option are vulnerable to this issue: options INET6 As a temporary workaround recompile the kernel with the above option commented out. The default NetBSD GENERIC kernels have this option enabled. 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/netinet6/icmp6.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 ========= Matt Thomas for the fix and FreeBSD for initial analysis of the issue. Revision History ================ 2008-10-27 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-SA2008-015.txt.asc Information about NetBSD and NetBSD security can be found at http://www.NetBSD.org/ and http://www.NetBSD.org/Security/. Copyright 2008, The NetBSD Foundation, Inc. All Rights Reserved. Redistribution permitted only in full, unmodified form. $NetBSD: NetBSD-SA2008-015.txt,v 1.4 2008/10/27 19:47:21 adrianp Exp $ -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (NetBSD) iQCVAwUBSQYcOD5Ru2/4N2IFAQIAkwP+MC4FjUdtYTdvw+ThoPbHI3GhnhWS+aao AxEPcyVxlYhC5RW0UzNlHrtFeFWKmr3eSV5MN30w3M9ddtOrwlj7UmTP350ZeEPN UYYWv6e0G3PnDqBwtAiFc/Hp+UiFQXVt32Z84Djnmvhs462YG+HoDhAr6bgdf08t RFPeQyd004k= =9FQk -----END PGP SIGNATURE-----