CVE-2007-4321
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.
Key facts
- CVSS score
- 6.8 (v2.0)
- Severity
- MEDIUM
- CVSS vector
AV:N/AC:M/Au:N/C:P/I:P/A:P- EPSS score
- 5.7% (93th percentile)
- In CISA KEV
- No
- In EU EUVD
- Yes (EUVD-2007-4304)
- Published
- August 14, 2007
- NVD last modified
- June 16, 2026
- Status
- Modified
EU Vulnerability Database (EUVD)
This vulnerability is also tracked by ENISA as EUVD-2007-4304 in the EU Vulnerability Database. Last updated in EUVD on August 7, 2024.
View on the EU Vulnerability DatabaseAffected products
- fail2ban / fail2ban
References
- http://bugs.gentoo.org/show_bug.cgi?id=181214
- http://osvdb.org/42484
- http://secunia.com/advisories/23237
- http://secunia.com/advisories/28374
- http://security.gentoo.org/glsa/glsa-200707-13.xml
- http://www.debian.org/security/2008/dsa-1456
- http://www.ossec.net/en/attacking-loganalysis.html
- http://www.securityfocus.com/bid/25117
Last updated September 17, 2026 · Source: NVD, CISA KEV, FIRST.org EPSS
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