CVE-2009-2666

CVE-2009-2666 is a medium-severity vulnerability in Fetchmail with a CVSS 2.0 base score of 6.4. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-310.

Key facts

Description

socket.c in fetchmail before 6.3.11 does not properly handle a '\0' character in a domain name in the subject's Common Name (CN) field of an X.509 certificate, which allows man-in-the-middle attackers to spoof arbitrary SSL servers via a crafted certificate issued by a legitimate Certification Authority, a related issue to CVE-2009-2408.

Frequently asked questions

What is CVE-2009-2666?
socket.c in fetchmail before 6.3.11 does not properly handle a '\0' character in a domain name in the subject's Common Name (CN) field of an X.509 certificate, which allows man-in-the-middle attackers to spoof arbitrary SSL servers via a crafted certificate issued by a legitimate Certification Authority, a related issue to CVE-2009-2408.
How severe is CVE-2009-2666?
CVE-2009-2666 has a CVSS 2.0 base score of 6.4, rated medium severity.
Is CVE-2009-2666 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (71st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2009-2666?
CVE-2009-2666 primarily affects Fetchmail. In total, 117 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2009-2666?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2009-2666 published?
CVE-2009-2666 was published on 2009-08-07 and last updated on 2026-06-16.

References

Affected products (117)

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