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Gentoo Linux Security Advisory GLSA 200701-01
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http://security.gentoo.org/
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Severity: Normal
Title: DenyHosts: Denial of Service
Date: January 03, 2007
Bugs: #157163
ID: 200701-01
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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
=================
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Package / Vulnerable / Unaffected
-------------------------------------------------------------------
1 app-admin/denyhosts < 2.6 >= 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 ">=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@xxxxxxxxxx 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
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