Vulnerability in Mozilla Firefox

CVE-2009-2408

Mozilla Network Security Services (NSS) before 3.12.3, Firefox before 3.0.13, Thunderbird before 2.0.0.23, and SeaMonkey before 1.1.18 do 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. NOTE: this was originally reported for Firefox before 3.5.

Vulnerability class: Improper Certificate Validation

EPSS: 0.057 (92.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2009-2408?
CVE-2009-2408 is a medium-severity vulnerability in Mozilla Firefox, classified under Improper Certificate Validation. CVSS score: 5.9/10. Published 2009-07-30.
How severe is CVE-2009-2408?
Medium severity. CVSS v3 base score is 5.9 out of 10.
Is CVE-2009-2408 known to be exploited?
3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.