VULNERABILITY INTELLIGENCE

CVE-2013-4238

CVSS score4.3 MEDIUM
EPSS probability5.35%
CISA KEVNot currently listed
Published2013-08-18
Last modified2026-06-16
CVSS vectorAV:N/AC:M/Au:N/C:N/I:P/A:N

Description

The ssl.match_hostname function in the SSL module in Python 2.6 through 3.4 does not properly handle a '\0' character in a domain name in the Subject Alternative Name 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.

Weakness classification

  • CWE-20: Improper Input Validation

Primary references