Gentoo: MIT Kerberos 5 Arbitrary remote code execution
Posted by Benjamin D. Thomas   
Gentoo Multiple vulnerabilities in MIT Kerberos 5 could potentially result in unauthenticated remote root code execution.
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Gentoo Linux Security Advisory                           GLSA 200704-02
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                                            http://security.gentoo.org/
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  Severity: High
     Title: MIT Kerberos 5: Arbitrary remote code execution
      Date: April 03, 2007
      Bugs: #171889
        ID: 200704-02

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Synopsis
========

Multiple vulnerabilities in MIT Kerberos 5 could potentially result in
unauthenticated remote root code execution.

Background
==========

MIT Kerberos 5 is a suite of applications that implement the Kerberos
network protocol.

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

    -------------------------------------------------------------------
     Package             /  Vulnerable  /                   Unaffected
    -------------------------------------------------------------------
  1  app-crypt/mit-krb5     < 1.5.2-r1                     >= 1.5.2-r1

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

The Kerberos telnet daemon fails to properly handle usernames allowing
unauthorized access to any account (CVE-2007-0956). The Kerberos
administration daemon, the KDC and possibly other applications using
the MIT Kerberos libraries are vulnerable to the following issues. The
krb5_klog_syslog function from the kadm5 library fails to properly
validate input leading to a stack overflow (CVE-2007-0957). The GSS-API
library is vulnerable to a double-free attack (CVE-2007-1216).

Impact
======

By exploiting the telnet vulnerability a remote attacker may obtain
access with root privileges. The remaining vulnerabilities may allow an
authenticated remote attacker to execute arbitrary code with root
privileges.

Workaround
==========

There is no known workaround at this time.

Resolution
==========

All MIT Kerberos 5 users should upgrade to the latest version:

    # emerge --sync
    # emerge --ask --oneshot --verbose ">=app-crypt/mit-krb5-1.5.2-r1"

References
==========

  [ 1 ] CVE-2007-0956
        http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2007-0956
  [ 2 ] CVE-2007-0957
        http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2007-0957
  [ 3 ] CVE-2007-1216
        http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2007-1216

Availability
============

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

  http://security.gentoo.org/glsa/glsa-200704-02.xml

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.

License
=======

Copyright 2007 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.

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