CVE catalog

CVE-2007-4321

fail2ban: CVE-2007-4321

[CVE catalog]

Severity
High
Published
Source
[NVD] · [CVE record]
EPSS
5.75% · Oct 25, 2026

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.

Vulnerable and fixed packages

Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.

DistributionPackageReleaseVersionStatus
Debianfail2bansid1.1.1-1fixed
Debianfail2banforky1.1.1-1fixed
Debianfail2bantrixie1.1.0-8fixed
Debianfail2banbookworm1.0.2-2fixed

Fixed-version evidence

DistributionPackageTypeReleaseFixed versionUrgencyOriginBugs
Debianfail2bansourcesid0.8.0-4mediumNot reported[438187]
Debianfail2bansourceforky0.8.0-4mediumNot reported[438187]
Debianfail2bansourcetrixie0.8.0-4mediumNot reported[438187]
Debianfail2bansourcebookworm0.8.0-4mediumNot reported[438187]

[Debian bug #438187]

OpenFactory catalog packages

[Debian 12 (Bookworm)]

  • [fail2ban]Fixed
    Details (2)

    • 1.0.2-2 · all · bookworm

      Fixed · Fixed: 0.8.0-4

      dsa · fail2ban · debian · bookworm; dsa · fail2ban · debian · 12

    • 1.0.2-2 · all · bookworm

      Fixed · Fixed: 0.8.0-4

      dsa · fail2ban · debian · bookworm; dsa · fail2ban · debian · 12

[Debian 13 (Trixie)]

  • [fail2ban]Fixed
    Details (2)

    • 1.1.0-8 · all · trixie

      Fixed · Fixed: 0.8.0-4

      dsa · fail2ban · debian · 13

    • 1.1.0-8 · all · trixie

      Fixed · Fixed: 0.8.0-4

      dsa · fail2ban · debian · 13

Observed:

References

[Debian Security Tracker] · [FIRST EPSS] · [OSV Package Vulnerability Database]