-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA512
=============================================================================
FreeBSD-SA-18:01.ipsec Security Advisory
The FreeBSD Project
Topic: ipsec validation and use-after-free
Category: core
Module: ipsec
Announced: 2018-03-07
Credits: Maxime Villard
Affects: All supported versions of FreeBSD.
Corrected: 2018-02-24 13:04:02 UTC (stable/11, 11.1-STABLE)
2018-03-07 05:53:35 UTC (releng/11.1, 11.1-RELEASE-p7)
2018-03-07 05:47:48 UTC (stable/10, 10.4-STABLE)
2018-03-07 05:53:35 UTC (releng/10.4, 10.4-RELEASE-p6)
2018-03-07 05:53:35 UTC (releng/10.3, 10.3-RELEASE-p27)
CVE Name: CVE-2018-6916
For general information regarding FreeBSD Security Advisories,
including descriptions of the fields above, security branches, and the
following sections, please visit <URL:https://security.FreeBSD.org/>.
I. Background
The IPsec suite of protocols provide network level security for IPv4 and IPv6
packets. FreeBSD includes software originally developed by the KAME project
which implements the various protocols that make up IPsec.
In IPsec, the IP Authentication Header (AH) is used to provide protection
against replay attacks and connectionless integrity and data origin
authentication for IP datagrams.
II. Problem Description
Due to a lack of strict checking, an attacker from a trusted host can
send a specially constructed IP packet that may lead to a system crash.
Additionally, a use-after-free vulnerability in the AH handling code could
cause unpredictable results.
III. Impact
Access to out of bounds or freed mbuf data can lead to a kernel panic or
other unpredictable results.
IV. Workaround
No workaround is available, but systems not using IPsec are not vulnerable.
V. Solution
Perform one of the following:
1) Upgrade your vulnerable system to a supported FreeBSD stable or
release / security branch (releng) dated after the correction date.
And reboot the system.
2) To update your vulnerable system via a binary patch:
Systems running a RELEASE version of FreeBSD on the i386 or amd64
platforms can be updated via the freebsd-update(8) utility:
# freebsd-update fetch
# freebsd-update install
And reboot the system
3) To update your vulnerable system via a source code patch:
The following patches have been verified to apply to the applicable
FreeBSD release branches.
a) Download the relevant patch from the location below, and verify the
detached PGP signature using your PGP utility.
[FreeBSD 10.x]
# fetch https://security.FreeBSD.org/patches/SA-18:01/ipsec-10.patch
# fetch https://security.FreeBSD.org/patches/SA-18:01/ipsec-10.patch.asc
# gpg --verify ipsec-10.patch.asc
[FreeBSD 11.1]
# fetch https://security.FreeBSD.org/patches/SA-18:01/ipsec-11.patch
# fetch https://security.FreeBSD.org/patches/SA-18:01/ipsec-11.patch.asc
# gpg --verify ipsec-11.patch.asc
b) Apply the patch. Execute the following commands as root:
# cd /usr/src
# patch < /path/to/patch
c) Recompile your kernel as described in
<URL:https://www.FreeBSD.org/handbook/kernelconfig.html> and reboot the
system.
VI. Correction details
The following list contains the correction revision numbers for each
affected branch.
Branch/path Revision
- -------------------------------------------------------------------------
stable/10/ r330565
releng/10.3/ r330566
releng/10.4/ r330566
stable/11/ r329907
releng/11.1/ r330566
- -------------------------------------------------------------------------
To see which files were modified by a particular revision, run the
following command, replacing NNNNNN with the revision number, on a
machine with Subversion installed:
# svn diff -cNNNNNN --summarize svn://svn.freebsd.org/base
Or visit the following URL, replacing NNNNNN with the revision number:
<URL:https://svnweb.freebsd.org/base?view=revision&revision=NNNNNN>
VII. References
<URL:https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-6916>
The latest revision of this advisory is available at
<URL:https://security.FreeBSD.org/advisories/FreeBSD-SA-18:01.ipsec.asc>
-----BEGIN PGP SIGNATURE-----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=Uzqo
-----END PGP SIGNATURE-----
