FreeBSD Security Advisory - A flaw in the OpenSSL handling of OCSP response verification could be exploited to cause a denial of service attack. OpenSSL has a weakness in the handling of CBC ciphersuites in SSL, TLS and DTLS. The weakness could reveal plaintext in a timing attack.
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FreeBSD-SA-13:03.openssl Security Advisory
The FreeBSD Project
Topic: OpenSSL multiple vulnerabilities
Category: contrib
Module: openssl
Announced: 2013-04-02
Affects: All supported versions of FreeBSD.
Corrected: 2013-03-08 17:28:40 UTC (stable/8, 8.3-STABLE)
2013-04-02 17:34:42 UTC (releng/8.3, 8.3-RELEASE-p7)
2013-03-14 17:48:07 UTC (stable/9, 9.1-STABLE)
2013-04-02 17:34:42 UTC (releng/9.0, 9.0-RELEASE-p7)
2013-04-02 17:34:42 UTC (releng/9.1, 9.1-RELEASE-p2)
CVE Name: CVE-2013-0166, CVE-2013-0169
For general information regarding FreeBSD Security Advisories,
including descriptions of the fields above, security branches, and the
following sections, please visit <URL:http://security.FreeBSD.org/>.
I. Background
FreeBSD includes software from the OpenSSL Project. The OpenSSL Project is
a collaborative effort to develop a robust, commercial-grade, full-featured
Open Source toolkit implementing the Secure Sockets Layer (SSL v2/v3)
and Transport Layer Security (TLS v1) protocols as well as a full-strength
general purpose cryptography library.
II. Problem Description
A flaw in the OpenSSL handling of OCSP response verification could be exploited
to cause a denial of service attack. [CVE-2013-0166]
OpenSSL has a weakness in the handling of CBC ciphersuites in SSL, TLS and
DTLS. The weakness could reveal plaintext in a timing attack. [CVE-2013-0169]
III. Impact
The Denial of Service could be caused in the OpenSSL server application by
using an invalid key. [CVE-2013-0166]
A remote attacker could recover sensitive information by conducting
an attack via statistical analysis of timing data with crafted packets.
[CVE-2013-0169]
IV. Workaround
No workaround is available.
V. Solution
Perform one of the following:
1) Upgrade your vulnerable system to a supported FreeBSD stable or
release / security branch (releng) dated dated after the correction
date.
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 8.3 and 9.0]
# fetch http://security.FreeBSD.org/patches/SA-13:03/openssl.patch
# fetch http://security.FreeBSD.org/patches/SA-13:03/openssl.patch.asc
# gpg --verify openssl.patch.asc
[FreeBSD 9.1]
# fetch http://security.FreeBSD.org/patches/SA-13:03/openssl-9.1.patch
# fetch http://security.FreeBSD.org/patches/SA-13:03/openssl-9.1.patch.asc
# gpg --verify openssl-9.1.patch.asc
b) Execute the following commands as root:
# cd /usr/src
# patch < /path/to/patch
Recompile the operating system using buildworld and installworld as
described in <URL:http://www.FreeBSD.org/handbook/makeworld.html>.
Restart the all deamons using the library, or reboot your the system.
3) 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
VI. Correction details
The following list contains the revision numbers of each file that was
corrected in FreeBSD.
Branch/path Revision
- -------------------------------------------------------------------------
stable/8/ r248057
releng/8.3/ r249029
stable/9/ r248272
releng/9.0/ r249029
releng/9.1/ r249029
- -------------------------------------------------------------------------
VII. References
CVE Name:
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2013-0169
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2013-0166
The latest revision of this advisory is available at
http://security.FreeBSD.org/advisories/FreeBSD-SA-13:03.openssl.asc
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