Executive Summary

Summary
Title DenyHosts: Denial of Service
Informations
Name GLSA-201406-23 First vendor Publication 2014-06-25
Vendor Gentoo Last vendor Modification 2014-06-25
Severity (Vendor) Normal Revision N/A

Security-Database Scoring CVSS v3

Cvss vector : N/A
Overall CVSS Score NA
Base Score NA Environmental Score NA
impact SubScore NA Temporal Score NA
Exploitabality Sub Score NA
 
Calculate full CVSS 3.0 Vectors scores

Security-Database Scoring CVSS v2

Cvss vector : (AV:N/AC:L/Au:N/C:N/I:N/A:P)
Cvss Base Score 5 Attack Range Network
Cvss Impact Score 2.9 Attack Complexity Low
Cvss Expoit Score 10 Authentication None Required
Calculate full CVSS 2.0 Vectors scores

Detail

Synopsis

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

Background

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

Description

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

Impact

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

Workaround

There is no known workaround at this time.

Resolution

All DenyHost users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=app-admin/denyhosts-2.6-r9"

References

[ 1 ] CVE-2013-6890 : http://nvd.nist.gov/nvd.cfm?cvename=CVE-2013-6890

Availability

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

http://security.gentoo.org/glsa/glsa-201406-23.xml

Original Source

Url : http://security.gentoo.org/glsa/glsa-201406-23.xml

CWE : Common Weakness Enumeration

% Id Name
100 % CWE-287 Improper Authentication

OVAL Definitions

Definition Id: oval:org.mitre.oval:def:21063
 
Oval ID: oval:org.mitre.oval:def:21063
Title: DSA-2826-1 deny hosts - Remote denial of ssh service
Description: Helmut Grohne discovered that deny hosts, a tool preventing SSH brute-force attacks, could be used to perform remote denial of service against the SSH daemon. Incorrectly specified regular expressions used to detect brute force attacks in authentication logs could be exploited by a malicious user to forge crafted login names in order to make deny hosts ban arbitrary IP addresses.
Family: unix Class: patch
Reference(s): DSA-2826-1
CVE-2013-6890
Version: 5
Platform(s): Debian GNU/Linux 6.0
Debian GNU/Linux 7
Debian GNU/kFreeBSD 6.0
Debian GNU/kFreeBSD 7
Product(s): denyhosts
Definition Synopsis:
Definition Id: oval:org.mitre.oval:def:28977
 
Oval ID: oval:org.mitre.oval:def:28977
Title: DSA-2826-2 -- denyhosts -- remote denial of ssh service
Description: Helmut Grohne discovered that denyhosts, a tool preventing SSH brute-force attacks, could be used to perform remote denial of service against the SSH daemon. Incorrectly specified regular expressions used to detect brute force attacks in authentication logs could be exploited by a malicious user to forge crafted login names in order to make denyhosts ban arbitrary IP addresses.
Family: unix Class: patch
Reference(s): DSA-2826-2
CVE-2013-6890
Version: 3
Platform(s): Debian GNU/Linux 6.0
Debian GNU/kFreeBSD 6.0
Debian GNU/Linux 7.0
Debian GNU/kFreeBSD 7.0
Product(s): denyhosts
Definition Synopsis:

CPE : Common Platform Enumeration

TypeDescriptionCount
Application 1
Os 3
Os 1

Nessus® Vulnerability Scanner

Date Description
2015-01-06 Name : The remote Fedora host is missing a security update.
File : fedora_2014-17067.nasl - Type : ACT_GATHER_INFO
2015-01-06 Name : The remote Fedora host is missing a security update.
File : fedora_2014-17081.nasl - Type : ACT_GATHER_INFO
2014-06-26 Name : The remote Gentoo host is missing one or more security-related patches.
File : gentoo_GLSA-201406-23.nasl - Type : ACT_GATHER_INFO
2013-12-23 Name : The remote Debian host is missing a security-related update.
File : debian_DSA-2826.nasl - Type : ACT_GATHER_INFO

Alert History

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0
1
Date Informations
2014-06-27 13:26:20
  • Multiple Updates
2014-06-26 00:24:08
  • First insertion