GLSA 200701-01 DenyHosts: Denial of Service
Posted on: 01/03/2007 07:45 PM

A new security update has been released for Gentoo Linux - DenyHosts: Denial of Service. Here the announcement:

Gentoo Linux Security Advisory GLSA 200701-01
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
http://security.gentoo.org/
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Severity: Normal
Title: DenyHosts: Denial of Service
Date: January 03, 2007
Bugs: #157163
ID: 200701-01

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

Synopsis
========

DenyHosts does not correctly parse log entries, potentially causing a
remote Denial of Service.

Background
==========

DenyHosts is designed to monitor SSH servers for repeated failed login
attempts.

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

-------------------------------------------------------------------
Package / Vulnerable / Unaffected
-------------------------------------------------------------------
1 app-admin/denyhosts lt; 2.6 gt;= 2.6

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

Tavis Ormandy of the Gentoo Linux Security Audit Team discovered that
DenyHosts used an incomplete regular expression to parse failed login
attempts.

Impact
======

A remote unauthenticated attacker can add arbitrary hosts to the
blacklist by attempting to login with a specially crafted username. An
attacker may use this to prevent legitimate users from accessing a host
remotely.

Workaround
==========

There is no known workaround at this time.

Resolution
==========

All DenyHosts users should upgrade to the latest version:

# emerge --sync
# emerge --ask --oneshot --verbose "gt;=app-admin/denyhosts-2.6"

References
==========

[ 1 ] CVE-2006-6301
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-6301

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

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

http://security.gentoo.org/glsa/glsa-200701-01.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



Printed from Linux Compatible (http://www.linuxcompatible.org/news/story/glsa_200701_01_denyhosts_denial_of_service.html)