<?xml version="1.0" encoding="utf-8"?> <!DOCTYPE glsa SYSTEM "http://www.gentoo.org/dtd/glsa.dtd"> <glsa id="200707-13"> <title>Fail2ban: Denial of Service</title> <synopsis> Fail2ban is vulnerable to a Denial of Service attack. </synopsis> <product type="ebuild">fail2ban</product> <announced>2007-07-28</announced> <revised count="02">2008-01-09</revised> <bug>181214</bug> <access>remote</access> <affected> <package name="net-analyzer/fail2ban" auto="yes" arch="*"> <unaffected range="ge">0.8.0-r1</unaffected> <vulnerable range="lt">0.8.0-r1</vulnerable> </package> </affected> <background> <p> Fail2ban is a tool for parsing log files and banning IP addresses which make too many password failures. </p> </background> <description> <p> A vulnerability has been discovered in Fail2ban when parsing log files. </p> </description> <impact type="normal"> <p> A remote attacker could send specially crafted SSH login banners to the vulnerable host, which would prevent any ssh connection to the host and result in a Denial of Service. </p> </impact> <workaround> <p> There is no known workaround at this time. </p> </workaround> <resolution> <p> All Fail2ban users should upgrade to the latest version: </p> <code> # emerge --sync # emerge --ask --oneshot --verbose ">=net-analyzer/fail2ban-0.8.0-r1"</code> </resolution> <references> <uri link="https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2007-4321">CVE-2007-4321</uri> <uri link="http://www.ossec.net/en/attacking-loganalysis.html#fail2ban">Original advisory</uri> </references> <metadata tag="requester" timestamp="2007-07-03T22:02:25Z"> aetius </metadata> <metadata tag="submitter" timestamp="2007-07-15T18:12:05Z"> p-y </metadata> <metadata tag="bugReady" timestamp="2007-07-15T18:13:27Z"> p-y </metadata> </glsa>