{"id":"DEBIAN-CVE-2007-4321","details":"fail2ban 0.8 and earlier 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 client protocol version identification containing an IP address string, a different vector than CVE-2006-6302.","modified":"2026-09-01T20:02:47.520679548Z","published":"2007-08-14T00:17:00Z","upstream":["CVE-2007-4321"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2007-4321"}],"affected":[{"package":{"name":"fail2ban","ecosystem":"Debian:12","purl":"pkg:deb/debian/fail2ban?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.8.0-4"}]}],"ecosystem_specific":{"urgency":"medium"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2007-4321.json"}},{"package":{"name":"fail2ban","ecosystem":"Debian:13","purl":"pkg:deb/debian/fail2ban?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.8.0-4"}]}],"ecosystem_specific":{"urgency":"medium"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2007-4321.json"}},{"package":{"name":"fail2ban","ecosystem":"Debian:14","purl":"pkg:deb/debian/fail2ban?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.8.0-4"}]}],"ecosystem_specific":{"urgency":"medium"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2007-4321.json"}}],"schema_version":"1.9.0"}