CVE-2013-4238
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.
Key facts
- CVSS score
- 4.3 (v2.0)
- Severity
- MEDIUM
- CVSS vector
AV:N/AC:M/Au:N/C:N/I:P/A:N- Weakness (CWE)
- CWE-20
- EPSS score
- 5.3% (93th percentile)
- In CISA KEV
- No
- In EU EUVD
- Yes (EUVD-2013-4142)
- Published
- August 18, 2013
- NVD last modified
- June 16, 2026
- Status
- Modified
EU Vulnerability Database (EUVD)
This vulnerability is also tracked by ENISA as EUVD-2013-4142 in the EU Vulnerability Database. Last updated in EUVD on August 6, 2024.
View on the EU Vulnerability DatabaseAffected products
- canonical / ubuntu linux
- opensuse / opensuse
- opensuse / opensuse
- opensuse / opensuse
- python / python
- python / python
- python / python
- python / python
- python / python
- python / python
- python / python
- python / python
- python / python
- python / python
- python / python
- python / python
- python / python
- python / python
- python / python
- python / python
- python / python
- python / python
- python / python
- python / python
- python / python
- python / python
- python / python
- python / python
- python / python
- python / python
- python / python
- python / python
- python / python
- python / python
- python / python
- python / python
- python / python
References
- http://bugs.python.org/issue18709(Patch)
- http://lists.opensuse.org/opensuse-security-announce/2020-01/msg00040.html
- http://lists.opensuse.org/opensuse-updates/2013-09/msg00026.html(Vendor Advisory)
- http://lists.opensuse.org/opensuse-updates/2013-09/msg00027.html(Vendor Advisory)
- http://lists.opensuse.org/opensuse-updates/2013-09/msg00028.html(Vendor Advisory)
- http://lists.opensuse.org/opensuse-updates/2013-09/msg00029.html(Vendor Advisory)
- http://lists.opensuse.org/opensuse-updates/2013-09/msg00042.html(Vendor Advisory)
- http://lists.opensuse.org/opensuse-updates/2013-09/msg00043.html(Vendor Advisory)
- http://rhn.redhat.com/errata/RHSA-2013-1582.html
- http://seclists.org/fulldisclosure/2014/Dec/23
- http://www.debian.org/security/2014/dsa-2880
- http://www.securityfocus.com/archive/1/534161/100/0/threaded
- http://www.ubuntu.com/usn/USN-1982-1(Vendor Advisory)
- http://www.vmware.com/security/advisories/VMSA-2014-0012.html
- https://bugzilla.redhat.com/show_bug.cgi?id=996381(Patch)
Last updated September 17, 2026 · Source: NVD, CISA KEV, FIRST.org EPSS
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