3571e53040
patches for easier mirroring, to eliminate a special copy, to make www.freebsd.org/security a full copy of security.freebsd.org and be eventually be the same. For now files are just sitting there. The symlinks are missing. Discussed on: www (repository location) Discussed with: simon (so)
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Text
113 lines
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Text
-----BEGIN PGP SIGNED MESSAGE-----
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Hash: SHA1
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=============================================================================
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FreeBSD-SA-08:09.icmp6 Security Advisory
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The FreeBSD Project
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Topic: Remote kernel panics on IPv6 connections
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Category: core
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Module: sys_netinet6
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Announced: 2008-09-03
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Credits: Tom Parker, Bjoern A. Zeeb
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Affects: All supported versions of FreeBSD.
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Corrected: 2008-09-03 19:09:47 UTC (RELENG_7, 7.1-PRERELEASE)
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2008-09-03 19:09:47 UTC (RELENG_7_0, 7.0-RELEASE-p4)
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2008-09-03 19:09:47 UTC (RELENG_6, 6.4-PRERELEASE)
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2008-09-03 19:09:47 UTC (RELENG_6_3, 6.3-RELEASE-p4)
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CVE Name: CVE-2008-3530
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For general information regarding FreeBSD Security Advisories,
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including descriptions of the fields above, security branches, and the
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following sections, please visit <URL:http://security.FreeBSD.org/>.
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I. Background
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IPv6 nodes use ICMPv6 amongst other things to report errors encountered
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while processing packets. The 'Packet Too Big Message' is sent in
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case a node cannot forward a packet because the size of the packet is
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larger than the MTU of next-hop link.
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II. Problem Description
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In case of an incoming ICMPv6 'Packet Too Big Message', there is an
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insufficient check on the proposed new MTU for a path to the destination.
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III. Impact
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When the kernel is configured to process IPv6 packets and has active
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IPv6 TCP sockets, a specifically crafted ICMPv6 'Packet Too Big
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Message' could cause the TCP stack of the kernel to panic,
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IV. Workaround
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Systems without INET6 / IPv6 support are not vulnerable and neither
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are systems which do not listen on any IPv6 TCP sockets and have no
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active IPv6 connections.
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Filter ICMPv6 'Packet Too Big Messages' using a firewall, but this
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will at the same time break PMTU support for IPv6 connections.
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V. Solution
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Perform one of the following:
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1) Upgrade your vulnerable system to 6-STABLE or 7-STABLE, or to the
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RELENG_6_3 or RELENG_7_0 security branch dated after the correction date.
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2) To patch your present system:
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The following patches have been verified to apply to FreeBSD 6.3 and
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FreeBSD 7.0 systems.
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a) Download the relevant patch from the location below, and verify the
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detached PGP signature using your PGP utility.
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# fetch http://security.FreeBSD.org/patches/SA-08:09/icmp6.patch
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# fetch http://security.FreeBSD.org/patches/SA-08:09/icmp6.patch.asc
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b) Apply the patch.
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# cd /usr/src
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# patch < /path/to/patch
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c) Recompile your kernel as described in
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<URL:http://www.FreeBSD.org/handbook/kernelconfig.html> and reboot the
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system.
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VI. Correction details
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The following list contains the revision numbers of each file that was
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corrected in FreeBSD.
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Branch Revision
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Path
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- -------------------------------------------------------------------------
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RELENG_6
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src/sys/netinet6/icmp6.c 1.62.2.11
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RELENG_6_3
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src/UPDATING 1.416.2.37.2.9
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src/sys/conf/newvers.sh 1.69.2.15.2.8
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src/sys/netinet6/icmp6.c 1.62.2.9.2.1
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RELENG_7
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src/sys/netinet6/icmp6.c 1.80.2.7
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RELENG_7_0
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src/UPDATING 1.507.2.3.2.8
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src/sys/conf/newvers.sh 1.72.2.5.2.8
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src/sys/netinet6/icmp6.c 1.80.4.1
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- -------------------------------------------------------------------------
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VII. References
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http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2008-3530
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The latest revision of this advisory is available at
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http://security.FreeBSD.org/advisories/FreeBSD-SA-08:09.icmp6.asc
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