What is CVE-2009-3767?

CVE-2009-3767 is a vulnerability in Apple Mac OS X, classified under Improper Certificate Validation. Published 2009-10-23.

Is CVE-2009-3767 known to be exploited?

2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Vulnerability in Apple Mac OS X

CVE-2009-3767

libraries/libldap/tls_o.c in OpenLDAP 2.2 and 2.4, and possibly other versions, when OpenSSL is used, 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.

Vulnerability class: Improper Certificate Validation

Published 2009-10-23 · last modified 2026-06-16.

CVSS v2 metric

CVSS v2 base score 4.3 (Medium). Vector: AV:N/AC:M/Au:N/C:N/I:P/A:N. This CVE predates CVSS v3 and has no v3 score from NVD.

EPSS exploit prediction

EPSS: 0.033 (88.0th percentile), scored 2026-09-29.

Low probability of exploitation in the next 30 days, but still tracked. 88th percentile — 88.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.033 · newest: 0.033 · change: 0.000

Affected products

Weakness classification (CWE)

CWE-295 — Improper Certificate Validation

Public proof-of-concept exploits

References

lists.fedoraproject.org/pipermail/package-announce/2010-March/036138.html (vendor-advisory, Third Party Advisory)
marc.info/ (mailing-list, Third Party Advisory)
security.gentoo.org/glsa/glsa-201406-36.xml (vendor-advisory, Third Party Advisory)
oval.cisecurity.org/repository/search/definition/oval:org.mitre.oval:def:11178 (signature, Third Party Advisory, vdb-entry)
www.vupen.com/english/advisories/2010/1858 (Third Party Advisory, vdb-entry)
secunia.com/advisories/40677 (Third Party Advisory, third-party-advisory)
oval.cisecurity.org/repository/search/definition/oval:org.mitre.oval:def:7274 (signature, Third Party Advisory, vdb-entry)
www.openldap.org/devel/cvsweb.cgi/libraries/libldap/tls_o.c.diff (Patch, Vendor Advisory)
www.vupen.com/english/advisories/2009/3056 (Third Party Advisory, vdb-entry)
www.redhat.com/support/errata/RHSA-2010-0543.html (vendor-advisory, Third Party Advisory)

Frequently asked questions

What is CVE-2009-3767?: CVE-2009-3767 is a vulnerability in Apple Mac OS X, classified under Improper Certificate Validation. Published 2009-10-23.
Is CVE-2009-3767 known to be exploited?: 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.