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Gentoo Linux Security Advisory                           GLSA 201507-15
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                                           https://security.gentoo.org/
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 Severity: Normal
    Title: OpenSSL: Alternate chains certificate forgery
     Date: July 10, 2015
     Bugs: #554172
       ID: 201507-15

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Synopsis
=======
Certain checks on untrusted certificates can be bypassed.

Background
=========
OpenSSL is an Open Source toolkit implementing the Secure Sockets Layer
(SSL v2/v3) and Transport Layer Security (TLS v1) as well as a general
purpose cryptography library.

Affected packages
================
    -------------------------------------------------------------------
     Package              /     Vulnerable     /            Unaffected
    -------------------------------------------------------------------
  1  dev-libs/openssl             < 1.0.1p                  >= 1.0.1p

Description
==========
During certificate verification, OpenSSL attempts to find an
alternative certificate chain if the first attempt to build such a
chain fails.

Impact
=====
A remote attacker could cause certain checks on untrusted
certificates to be bypassed, such as the CA flag, enabling them to use
a valid leaf certificate to act as a CA and "issue" an invalid
certificate.

Workaround
=========
There is no known workaround at this time.

Resolution
=========
All OpenSSL users should upgrade to the latest version:

  # emerge --sync
  # emerge --ask --oneshot --verbose ">=dev-libs/openssl-1.0.1p"

References
=========
[ 1 ] CVE-2015-1793
      http://nvd.nist.gov/nvd.cfm?cvename=CVE-2015-1793

Availability
===========
This GLSA and any updates to it are available for viewing at
the Gentoo Security Website:

 https://security.gentoo.org/glsa/201507-15

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
https://bugs.gentoo.org.

License
======
Copyright 2015 Gentoo Foundation, Inc; referenced text
belongs to its owner(s).

The contents of this document are licensed under the
Creative Commons - Attribution / Share Alike license.

https://creativecommons.org/licenses/by-sa/2.5/