Protect yourself against future threats.
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
===========================================================================
AUSCERT Security Bulletin
ASB-2013.0016
A vulnerability has been identified in GnuTLS
8 February 2013
===========================================================================
AusCERT Security Bulletin Summary
---------------------------------
Product: GnuTLS
Operating System: Windows
UNIX variants (UNIX, Linux, OSX)
Impact/Access: Access Privileged Data -- Remote with User Interaction
Resolution: Patch/Upgrade
CVE Names: CVE-2013-1619
Member content until: Sunday, March 10 2013
OVERVIEW
A vulnerability has been identified in GnuTLS prior to versions 3.1.7,
3.0.28 and 2.12.23. [1]
IMPACT
The vendor has provided the following description regarding this
vulnerability:
"Nadhem Alfardan and Kenny Paterson devised an attack that recovers
some bits of the plaintext of a GnuTLS session that utilizes that CBC
ciphersuites, by using timing information.
In order for the attack to work the client must operate as follows.
It connects to a server, it sends some (encrypted) data that will be
intercepted by the attacker, who will terminate the client's
connection abnormally (i.e. the client will receive a premature
termination error). The client should repeat that, multiple times." [1]
MITIGATION
The vendor has provided the following mitigations which includes
the application of a patch:
"Do not enable the CBC ciphersuites, prefer ARCFOUR or GCM modes.
Upgrade to the latest GnuTLS version (3.1.7, 3.0.28, or 2.12.23)." [1]
REFERENCES
[1] TLS CBC padding timing attack
http://www.gnutls.org/security.html#GNUTLS-SA-2013-1
AusCERT has made every effort to ensure that the information contained
in this document is accurate. However, the decision to use the information
described is the responsibility of each user or organisation. The decision to
follow or act on information or advice contained in this security bulletin is
the responsibility of each user or organisation, and should be considered in
accordance with your organisation's site policies and procedures. AusCERT
takes no responsibility for consequences which may arise from following or
acting on information or advice contained in this security bulletin.
===========================================================================
Australian Computer Emergency Response Team
The University of Queensland
Brisbane
Qld 4072
Internet Email: auscert@auscert.org.au
Facsimile: (07) 3365 7031
Telephone: (07) 3365 4417 (International: +61 7 3365 4417)
AusCERT personnel answer during Queensland business hours
which are GMT+10:00 (AEST).
On call after hours for member emergencies only.
===========================================================================
-----BEGIN PGP SIGNATURE-----
Comment: http://www.auscert.org.au/render.html?it=1967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=ka4D
-----END PGP SIGNATURE-----