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Gentoo Linux Security Advisory [ERRATA UPDATE]        GLSA 200507-20:02
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                                            https://security.gentoo.org/
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  Severity: Low
     Title: Shorewall: Security policy bypass
      Date: July 22, 2005
   Updated: September 14, 2005
      Bugs: #99398
        ID: 200507-20:02

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Errata
=====
The "unaffected" version was incorrectly set to 2.4.1 in the initial
advisory, the correct "unaffected" version is 2.4.2.

The corrected sections appear below.

Synopsis
=======
A vulnerability in Shorewall allows clients authenticated by MAC
address filtering to bypass all other security rules.

Background
=========
Shorewall is a high level tool for configuring Netfilter, the firewall
facility included in the Linux Kernel.

Affected packages
================
    -------------------------------------------------------------------
     Package                 /  Vulnerable  /               Unaffected
    -------------------------------------------------------------------
  1  net-firewall/shorewall      <= 2.4.1                     >= 2.4.2

Description
==========
Shorewall fails to enforce security policies if configured with
"MACLIST_DISPOSITION" set to "ACCEPT" or "MACLIST_TTL" set to a value
greater or equal to 0.

Impact
=====
A client authenticated by MAC address filtering could bypass all
security policies, possibly allowing him to gain access to restricted
services. The default installation has MACLIST_DISPOSITION=REJECT and
MACLIST_TTL=(blank) (equivalent to 0). This can be checked by looking
at the settings in /etc/shorewall/shorewall.conf

Workaround
=========
Set "MACLIST_TTL" to "0" and "MACLIST_DISPOSITION" to "REJECT" in the
Shorewall configuration file (usually /etc/shorewall/shorewall.conf).

Resolution
=========
All Shorewall users should upgrade to the latest available version:

    # emerge --sync
    # emerge --ask --oneshot --verbose net-firewall/shorewall

References
=========
  [ 1 ] CAN-2005-2317
        http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2005-2317
  [ 2 ] Shorewall Announcement
        https://shorewall.org/News.htm

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

  https://security.gentoo.org/glsa/200507-20

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 2005 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/2.0/