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)
119 lines
4 KiB
Text
119 lines
4 KiB
Text
-----BEGIN PGP SIGNED MESSAGE-----
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Hash: SHA1
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=============================================================================
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FreeBSD-SA-04:06.ipv6 Security Advisory
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The FreeBSD Project
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Topic: setsockopt(2) IPv6 sockets input validation error
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Category: core
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Module: kernel
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Announced: 2004-03-29
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Credits: Katsuhisa ABE, Colin Percival
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Affects: FreeBSD 5.2-RELEASE
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Corrected: 2004-03-29 14:01:33 UTC (RELENG_5_2, 5.2.1-RELEASE-p4)
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CVE Name: CAN-2004-0370
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FreeBSD only: YES
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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
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<URL:http://www.freebsd.org/security/>.
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I. Background
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IPv6 is a new Internet Protocol, designed to replace (and avoid many of
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the problems with) the current Internet Protocol (version 4). FreeBSD
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uses the KAME Project IPv6 implementation.
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Applications may manipulate the behavior of an IPv6 socket using the
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setsockopt(2) system call.
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II. Problem Description
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A programming error in the handling of some IPv6 socket options within
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the setsockopt(2) system call may result in memory locations being
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accessed without proper validation. While the problem originates in
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code from the KAME Project, it does not affect other operating systems.
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III. Impact
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It may be possible for a local attacker to read portions of kernel
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memory, resulting in disclosure of sensitive information. A local
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attacker can cause a system panic.
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IV. Workaround
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Do one of the following:
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1) Disable IPv6 entirely by following these steps:
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- Remove or comment out any lines mentioning `INET6' from your
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kernel configuration file, and recompile your kernel as described
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in <URL:http://www.freebsd.org/handbook/kernelconfig.html>.
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- Reboot your system.
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2) If all untrusted users are confined within a jail(8), ensure that
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the security.jail.socket_unixiproute_only sysctl is set to 1 and
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verify that no IPv6 sockets are currently open:
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# sysctl security.jail.socket_unixiproute_only=1
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# sockstat -6
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This will restrict jailed processes to creating UNIX domain, IPv4, and
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routing sockets, which are not vulnerable to this problem; note however
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that processes inside a jail may still be able to inherit IPv6 sockets
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from outside the jail, so this may not be sufficient for all systems.
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V. Solution
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Do one of the following:
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1) Upgrade your vulnerable system to the RELENG_5_2 security branch
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dated after the correction date.
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2) To patch your present system:
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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 ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-04:06/ipv6.patch
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# fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-04:06/ipv6.patch.asc
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b) Execute the following commands as root:
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# cd /usr/src
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# patch < /path/to/patch
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c) Recompile the 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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d) Install updated kernel headers.
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# cd /usr/src/include
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# make install
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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_5_2
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src/UPDATING 1.282.2.12
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src/sys/netinet6/ip6_output.c 1.71.2.2
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src/sys/netinet/ip6.h 1.10.2.1
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src/sys/conf/newvers.sh 1.56.2.11
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- -------------------------------------------------------------------------
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