OpenSSL Security Advisory [28th September 2006]

[wbrana at gmail dot com]

OpenSSL Security Advisory [28th September 2006]

New OpenSSL releases are now available to correct four security
issues.


ASN.1 Denial of Service Attacks (CVE-2006-2937, CVE-2006-2940)
==============================================================

Vulnerability
-------------

Dr. S. N. Henson recently developed an ASN.1 test suite for NISCC
(www.niscc.gov.uk).  When the test suite was run against OpenSSL two
denial of service vulnerabilities were discovered:

1. During the parsing of certain invalid ASN.1 structures an error
condition is mishandled.  This can result in an infinite loop which
consumes system memory (CVE-2006-2937).  (This issue did not affect
OpenSSL versions prior to 0.9.7)

2. Certain types of public key can take disproportionate amounts of
time to process. This could be used by an attacker in a denial of
service attack (CVE-2006-2940).

Any code which uses OpenSSL to parse ASN.1 data from untrusted sources
is affected. This includes SSL servers which enable client
authentication and S/MIME applications.

Acknowledgements
----------------

The OpenSSL team thank Dr S. N. Henson of Open Network Security and NISCC
for funding the ASN.1 test suite project.


SSL_get_shared_ciphers() buffer overflow (CVE-2006-3738)
========================================================

Vulnerability
-------------

A buffer overflow was discovered in the SSL_get_shared_ciphers()
utility function.  An attacker could send a list of ciphers to an
application that uses this function and overrun a buffer
(CVE-2006-3738).

Acknowledgements
----------------

The OpenSSL team thank Tavis Ormandy and Will Drewry of the Google
Security Team for reporting this issue.


SSLv2 Client Crash (CVE-2006-4343)
==================================

Vulnerability
-------------

A flaw in the SSLv2 client code was discovered. When a client
application used OpenSSL to create an SSLv2 connection to a malicious
server, that server could cause the client to crash (CVE-2006-4343).

Acknowledgements
----------------

The OpenSSL team thank Tavis Ormandy and Will Drewry of the Google
Security Team for reporting this issue.


Recommendations
===============

These vulnerabilities are resolved in the following versions of OpenSSL:

  - in the 0.9.7 branch, version 0.9.7l (or later);
  - in the 0.9.8 branch, version 0.9.8d (or later).

OpenSSL 0.9.8d and OpenSSL 0.9.7l are available for download via
HTTP and FTP from the following master locations (you can find the
various FTP mirrors under http://www.openssl.org/source/mirror.html):

   o http://www.openssl.org/source/
   o ftp://ftp.openssl.org/source/

The distribution file names are:

   o openssl-0.9.8d.tar.gz
     MD5 checksum: 8ed1853538e1d05a1f5ada61ebf8bffa
     SHA1 checksum: 4136fba00303a3d319d2052bfa8e1f09a2e12fc2

   o openssl-0.9.7l.tar.gz
     MD5 checksum: b21d6e10817ddeccf5fbe1379987333e
     SHA1 checksum: f0e4136639b10cbd1227c4f7350ff7ad406e575d

The checksums were calculated using the following commands:

   openssl md5 openssl-0.9*.tar.gz
   openssl sha1 openssl-0.9*.tar.gz

After upgrading make sure to recompile any applications statically
linked to OpenSSL libraries and restart all applications that use
OpenSSL.


References
==========

URL for this Security Advisory:
http://www.openssl.org/news/secadv_20060928.txt

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