CVE-2013-6890
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.
Does this matter?
A public exploit is published in Exploit-DB (verified), so the technical barrier is gone even though the severity is medium and EPSS is 8.9%. Treat it as high on anything reachable from the internet.
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.
- CVSS 2.0
- 5.0 MEDIUMAV:N/AC:L/Au:N/C:N/I:N/A:P
- EPSS
- 8.90% probability · 95th percentile
- Public exploits
- 1 in Exploit-DB · verified · first 19 December 2013
- CISA KEV
- Not listed
- Weakness
- CWE-287
- Affected
- debian/debian linux · fedoraproject/fedora · phil schwartz/denyhosts
- Source
- cve@mitre.org
EPSS 8.9% since 26 October 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
Public exploits (1)
Entries in Exploit-DB that cite this CVE. Links go to the Exploit-DB page and to the file in the public repository; nothing is hosted here. A verified tick means the Exploit-DB team confirmed the exploit works against the stated version.
References
- http://seclists.org/oss-sec/2013/q4/535
- http://secunia.com/advisories/56239Vendor Advisory
- 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/56239Vendor Advisory
- http://www.debian.org/security/2013/dsa-2826
- https://bugzilla.redhat.com/show_bug.cgi?id=1045982
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.