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DenyHosts: Denial of Service


1.  Gentoo Linux Security Advisory

Version Information

Advisory Reference GLSA 201406-23 / denyhost
Release Date June 25, 2014
Latest Revision June 25, 2014: 1
Impact normal
Exploitable remote
Package Vulnerable versions Unaffected versions Architecture(s)
app-admin/denyhosts < 2.6-r9 >= 2.6-r9 All supported architectures

Related bugreports: #495130


A vulnerability in DenyHosts could allow a remote attacker to create a Denial of Service condition.

2.  Impact Information


DenyHosts is a script intended to be run by Linux system administrators to help thwart SSH server attacks.


DenyHosts does not properly define the regular expressions used when parsing SSH authentication logs.


A remote attacker could possibly cause a Denial of Service condition via a crafted login name.

3.  Resolution Information


There is no known workaround at this time.


All DenyHost users should upgrade to the latest version:

Code Listing 3.1: Resolution

  # emerge --sync
  # emerge --ask --oneshot --verbose ">=app-admin/denyhosts-2.6-r9"

4.  References


Page updated June 25, 2014

Summary: This is a Gentoo Linux Security Advisory

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