Gentoo Linux Security Advisory 200403-03: Multiple OpenSSL Vulnerabilities

[Aida Escriva-Sammer <aescriva () gentoo org>]

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Gentoo Linux Security Advisory                           GLSA 200403-03
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                                             http://security.gentoo.org
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  Severity: Normal
     Title: Multiple OpenSSL Vulnerabilities
      Date: March 17, 2004
      Bugs: #44941
        ID: 200403-03

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Synopsis
========

Three vulnerabilities have been found in OpenSSL via a commercial test
suite for the TLS protocol developed by Codenomicon Ltd.

Background
==========

The OpenSSL Project is a collaborative effort to develop a robust,
commercial-grade, full-featured, and 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.

Affected packages
=================

    -------------------------------------------------------------------
     Package           /   Vulnerable   /                   Unaffected
    -------------------------------------------------------------------
     dev-libs/openssl       <= 0.9.7c                        >= 0.9.7d
     dev-libs/openssl       <= 0.9.7c                        == 0.9.6m

Description
===========

1. Testing performed by the OpenSSL group using the Codenomicon TLS
   Test Tool uncovered a null-pointer assignment in the
   do_change_cipher_spec() function. A remote attacker could perform a
   carefully crafted SSL/TLS handshake against a server that used the
   OpenSSL library in such a way as to cause OpenSSL to crash.
   Depending on the application this could lead to a denial of service.
   All versions of OpenSSL from 0.9.6c to 0.9.6l inclusive and from
   0.9.7a to 0.9.7c inclusive are affected by this issue.

2. A flaw has been discovered in SSL/TLS handshaking code when using
   Kerberos ciphersuites. A remote attacker could perform a carefully
   crafted SSL/TLS handshake against a server configured to use
   Kerberos ciphersuites in such a way as to cause OpenSSL to crash.
   Most applications have no ability to use Kerberos cipher suites and
   will therefore be unaffected. Versions 0.9.7a, 0.9.7b, and 0.9.7c of
   OpenSSL are affected by this issue.

3. Testing performed by the OpenSSL group using the Codenomicon TLS
   Test Tool uncovered a bug in older versions of OpenSSL 0.9.6 that
   can lead to a Denial of Service attack (infinite loop). This issue
   was traced to a fix that was added to OpenSSL 0.9.6d some time ago.
   This issue will affect vendors that ship older versions of OpenSSL
   with backported security patches.

Impact
======

Although there are no public exploits known for bug, users are
recommended to upgrade to ensure the security of their infrastructure.

Workaround
==========

There is no immediate workaround; a software upgrade is required. The
vulnerable function in the code has been rewritten.

Resolution
==========

All users are recommened to upgrade openssl to either 0.9.7d or 0.9.6m:

    # emerge sync
    # emerge -pv ">=dev-libs/openssl-0.9.7d"
    # emerge ">=dev-libs/openssl-0.9.7d"

Concerns?
=========

Security is a primary focus of Gentoo Linux and ensuring the
confidentiality and security of our users machines is of utmost
importance to us. Any security concerns should be addressed to
security () gentoo org or alternatively, you may file a bug at
http://bugs.gentoo.org.

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