{"id":"CVE-2007-4321","aliases":["DEBIAN-CVE-2007-4321","DSA-1456-1","EUVD-2007-4304","GHSA-5jfx-9p58-q8pj"],"status":"published","title":"fail2ban 0.8 and earlier does not properly parse sshd log files, which allows remote attackers to...","description":"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.","severity":{"version":"2.0","score":6.8,"vector":"AV:N/AC:M/Au:N/C:P/I:P/A:P","level":"medium","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-08","score":0.05748,"percentile":0.93118,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":true,"fix_available":true},"published":"2007-08-14T00:00:00Z","modified":"2026-10-21T17:47:31Z","exploits":[{"source":"exploitdb","id":"EDB-30430","title":"Fail2ban 0.8 - Remote Denial of Service","type":"dos","platform":"linux","date":"2007-07-28","verified":true,"url":"https://www.exploit-db.com/exploits/30430"}],"fixes":[{"ecosystem":"Debian:12","package":"fail2ban","fixed_in":["0.8.0-4"],"sources":["osv"]},{"ecosystem":"Debian:13","package":"fail2ban","fixed_in":["0.8.0-4"],"sources":["osv"]},{"ecosystem":"Debian:14","package":"fail2ban","fixed_in":["0.8.0-4"],"sources":["osv"]},{"ecosystem":"Debian:4.0","package":"fail2ban","fixed_in":["0.7.5-2etch1"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"Debian:12","package":"fail2ban","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.8.0-4"}]}]},{"source":"osv","ecosystem":"Debian:13","package":"fail2ban","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.8.0-4"}]}]},{"source":"osv","ecosystem":"Debian:14","package":"fail2ban","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.8.0-4"}]}]},{"source":"osv","ecosystem":"Debian:4.0","package":"fail2ban","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.7.5-2etch1"}]}],"versions":["0.7.5-2"]}],"products":[{"vendor":"fail2ban","product":"fail2ban"}],"references":[{"url":"http://www.debian.org/security/2008/dsa-1456","tags":["vendor-advisory","x_refsource_DEBIAN","x_transferred","advisory"]},{"url":"http://secunia.com/advisories/23237","tags":["third-party-advisory","x_refsource_SECUNIA","x_transferred","advisory"]},{"url":"http://osvdb.org/42484","tags":["vdb-entry","x_refsource_OSVDB","x_transferred","web"]},{"url":"http://www.securityfocus.com/bid/25117","tags":["vdb-entry","x_refsource_BID","x_transferred","web"]},{"url":"http://secunia.com/advisories/28374","tags":["third-party-advisory","x_refsource_SECUNIA","x_transferred","advisory"]},{"url":"http://bugs.gentoo.org/show_bug.cgi?id=181214","tags":["x_refsource_MISC","x_transferred","web"]},{"url":"http://security.gentoo.org/glsa/glsa-200707-13.xml","tags":["vendor-advisory","x_refsource_GENTOO","x_transferred","advisory"]},{"url":"http://www.ossec.net/en/attacking-loganalysis.html","tags":["x_refsource_MISC","x_transferred","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2007-4321"},{"url":"https://github.com/advisories/GHSA-5jfx-9p58-q8pj"},{"url":"https://security-tracker.debian.org/tracker/CVE-2007-4321","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2007-4321","description":"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.","status":"published","published":"2007-08-14T00:00:00Z","modified":"2024-08-07T14:53:55.834Z","updated_at":"2026-11-02T13:33:41.472948Z"}],"euvd":[{"id":"EUVD-2007-4304","description":"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.","status":"published","published":"2007-08-14T00:00:00Z","modified":"2024-08-07T14:53:55Z","updated_at":"2026-11-03T01:16:22.0225Z"}],"ghsa":[{"id":"GHSA-5jfx-9p58-q8pj","title":"fail2ban 0.8 and earlier does not properly parse sshd log files, which allows remote attackers to...","description":"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.","status":"published","published":"2022-05-01T18:22:23Z","modified":"2023-01-31T05:04:15Z","updated_at":"2026-11-02T14:48:38.150318Z"}],"nvd":[{"id":"CVE-2007-4321","description":"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.","status":"published","published":"2007-08-14T00:17:00Z","modified":"2026-06-16T22:43:48.533Z","cvss":[{"version":"2.0","score":6.8,"vector":"AV:N/AC:M/Au:N/C:P/I:P/A:P","level":"medium","assessor":"primary"}],"updated_at":"2026-11-02T14:01:19.102336Z"}],"osv":[{"id":"CVE-2007-4321","description":"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.","status":"published","published":"2007-08-14T00:17:00Z","modified":"2026-04-10T03:39:01.552351Z","updated_at":"2026-11-02T15:43:57.178433Z"},{"id":"DEBIAN-CVE-2007-4321","description":"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.","status":"published","published":"2007-08-14T00:17:00Z","modified":"2026-10-21T17:47:31.880458336Z","updated_at":"2026-11-02T15:45:23.411908Z"},{"id":"DSA-1456-1","title":"fail2ban","status":"published","published":"2008-01-09T00:00:00Z","modified":"2026-03-09T01:01:01.115752Z","updated_at":"2026-11-02T15:46:14.285228Z"}]}}