DenyHosts 2.5 does not properly parse sshd log files, which allows remote attackers to add arbitrary hosts to the /etc/hosts.deny file and …

DenyHosts 2.5 does not properly parse sshd log files, which allows remote attackers to add arbitrary hosts to the /etc/hosts.deny file and cause a denial of service by adding arbitrary IP addresses to the sshd log file, as demonstrated by logging in via ssh with a login name containing certain strings with an IP address, which is not properly handled by a regular expression.