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FreeBSD Security Advisory FreeBSD-SA-20:10.ipfw

Posted on 21 April 2020
FreeBSD security notificat

=============================================================================FreeBSD-SA-20:10.ipfw Security Advisory
The FreeBSD Project

Topic: ipfw invalid mbuf handling

Category: core
Module: kernel
Announced: 2020-04-21
Credits: Maxime Villard
All supported versions of FreeBSD.
Corrected: 2019-12-23 10:02:55 UTC (stable/12, 12.1-STABLE)
2020-04-21 15:52:22 UTC (releng/12.1, 12.1-RELEASE-p4)
2019-12-23 10:06:32 UTC (stable/11, 11.3-STABLE)
2020-04-21 15:52:22 UTC (releng/11.3, 11.3-RELEASE-p8)
CVE Name: CVE-2019-5614, CVE-2019-15874


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 ipfw system facility allows filtering, redirecting, and other operations
on IP packets travelling through network interfaces.

II. Problem Description

Incomplete packet data validation may result in accessing out-of-bounds
memory (CVE-2019-5614) or may access memory after it has been freed
(CVE-2019-15874).

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. Systems not using the ipfw firewall 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.

[FreeBSD 11.3]
# fetch https://security.FreeBSD.org/patches/SA-20:10/ipfw.11.patch
# fetch https://security.FreeBSD.org/patches/SA-20:10/ipfw.11.patch.asc
# gpg --verify ipfw.11.patch.asc

[FreeBSD 12.1]
# fetch https://security.FreeBSD.org/patches/SA-20:10/ipfw.12.patch
# fetch https://security.FreeBSD.org/patches/SA-20:10/ipfw.12.patch.asc
# gpg --verify ipfw.12.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/12/ r356035
releng/12.1/ r360149
stable/11/ r356036
releng/11.3/ r360149
- -------------------------------------------------------------------------

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

<other info on vulnerability>

<URL:https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-5614>
<URL:https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-15874>

The latest revision of this advisory is available at
<URL:https://security.FreeBSD.org/advisories/FreeBSD-SA-20:10.ipfw.asc>

 

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