CVE-2007-4323: DenyHosts 2.6 does not properly parse sshd log files, which allows remote attackers to add arbitrary hosts...

Security readout for executives and security teams

DenyHosts 2.6 can be tricked by crafted SSH log content into adding attacker-chosen IP addresses to /etc/hosts.deny. That can block legitimate SSH access and create a denial of service for administrators or users who depend on SSH. Exposure is likely limited to systems running DenyHosts 2.6 with automated blocking based on sshd logs. Business impact depends on whether SSH access is operationally critical and whether /etc/hosts.deny controls access on the host. Treat as a targeted availability risk for older systems using DenyHosts. Prioritize internet-facing or remotely administered servers because the practical harm is loss of SSH access, not data theft or code execution. Mitigation focus: Identify hosts running DenyHosts 2.6 or package builds based on it.; Review Gentoo, Red Hat, and project guidance for fixed packages or configuration changes.; Temporarily disable automated deny-list updates on critical SSH administration paths if needed..

Prepared

Jun 29, 2026, 04:07 UTC (UTC+00:00)

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.