What’s Vulnerable › Vulnerabilities

CVE-2013-6890

• Severity: medium (CVSS 5.0 v2.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 8.9% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2013-12-23 · updated 2026-06-17
• Weakness: CWE-287

Description

denyhosts 2.6 uses an incorrect regular expression when analyzing authentication logs, which allows remote attackers to cause a denial of service (incorrect block of IP addresses) via crafted login names.

Affected products

• Debian Linux: 6.0, 7.0, 7.1
• Fedoraproject Fedora: all versions
• Phil Schwartz Denyhosts: 2.6

References

• http://seclists.org/oss-sec/2013/q4/535
• http://secunia.com/advisories/56239
• http://www.debian.org/security/2013/dsa-2826
• https://bugzilla.redhat.com/show_bug.cgi?id=1045982
• http://seclists.org/oss-sec/2013/q4/535
• http://secunia.com/advisories/56239
• http://www.debian.org/security/2013/dsa-2826
• https://bugzilla.redhat.com/show_bug.cgi?id=1045982

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