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FreeBSD Security Advisory FreeBSD-SA-20:02.ipsec

Posted on 28 January 2020
FreeBSD security notificat

=============================================================================FreeBSD-SA-20:02.ipsec Security Advisory
The FreeBSD Project

Topic: Missing IPsec anti-replay window check

Category: core
Module: kernel
Announced: 2020-01-28
Credits: Jean-Francois HREN
Affects: FreeBSD 12.0 only
Corrected: 2020-01-28 18:56:46 UTC (releng/12.0, 12.0-RELEASE-p13)
CVE Name: CVE-2019-5613

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

IPsec is a suite of protocols providing data authentication, integrity, and
confidentiality between two networked hosts.

II. Problem Description

A missing check means that an attacker can reinject an old packet and it will
be accepted and processed by the IPsec endpoint.

III. Impact

The impact depends on the higher-level protocols in use over IPsec. For
example, an attacker who can capture and inject packets could cause an action
that was intentionally performed once to be repeated.

IV. Workaround

No workaround is available. Systems not using IPsec are not vulnerable.

V. Solution

Upgrade your vulnerable system to a supported FreeBSD stable or
release / security branch (releng) dated after the correction date,
and reboot.

Perform one of the following:

1) 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
# shutdown -r +10min "Rebooting for a security update"

2) 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.

# fetch https://security.FreeBSD.org/patches/SA-20:02/ipsec.patch
# fetch https://security.FreeBSD.org/patches/SA-20:02/ipsec.patch.asc
# gpg --verify ipsec.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
- -------------------------------------------------------------------------
releng/12.0/ r357218
- -------------------------------------------------------------------------

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-2019-5613>

The latest revision of this advisory is available at
<URL:https://security.FreeBSD.org/advisories/FreeBSD-SA-20:02.ipsec.asc>

 

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