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FreeBSD Security Advisory FreeBSD-SA-15:03.sctp

Posted on 27 January 2015
FreeBSD security notificat

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FreeBSD-SA-15:03.sctp Security Advisory
The FreeBSD Project

Topic: SCTP stream reset vulnerability

Category: core
Module: sctp
Announced: 2015-01-27
Credits: Gerasimos Dimitriadis
Affects: All supported versions of FreeBSD.
Corrected: 2015-01-27 19:36:08 UTC (stable/10, 10.1-STABLE)
2015-01-27 19:37:02 UTC (releng/10.1, 10.1-RELEASE-p5)
2015-01-27 19:37:02 UTC (releng/10.0, 10.0-RELEASE-p17)
2015-01-27 19:36:08 UTC (stable/9, 9.3-STABLE)
2015-01-27 19:37:02 UTC (releng/9.3, 9.3-RELEASE-p9)
2015-01-27 19:36:08 UTC (stable/8, 8.4-STABLE)
2015-01-27 19:37:02 UTC (releng/8.4, 8.4-RELEASE-p23)
CVE Name: CVE-2014-8613

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

SCTP protocol provides reliable, flow-controlled, two-way transmission
of data. It is a message oriented protocol and can support the SOCK_STREAM
and SOCK_SEQPACKET abstractions.

II. Problem Description

The input validation of received SCTP RE_CONFIG chunks is insufficient,
and can result in a NULL pointer deference later.

III. Impact

A remote attacker who can send a malformed SCTP packet to a FreeBSD system
that serves SCTP can cause a kernel panic, resulting in a Denial of
Service.

IV. Workaround

On FreeBSD 10.1 or later systems, the system administrator can set
net.inet.sctp.reconfig_enable to 0 to disable processing of RE_CONFIG
chunks. This workaround is not available on earlier FreeBSD releases,
but systems that do not serve SCTP connections 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.

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

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.

# fetch https://security.FreeBSD.org/patches/SA-15:03/sctp.patch
# fetch https://security.FreeBSD.org/patches/SA-15:03/sctp.patch.asc
# gpg --verify sctp.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/8/ r277807
releng/8.4/ r277808
stable/9/ r277807
releng/9.3/ r277808
stable/10/ r277807
releng/10.0/ r277808
releng/10.1/ r277808
- -------------------------------------------------------------------------

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-2014-8613>

The latest revision of this advisory is available at
<URL:https://security.FreeBSD.org/advisories/FreeBSD-SA-15:03.sctp.asc>

 

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