CVE-2013-4314

mediumpriority · track · 17EPSS 0.012 · 68 %ileEUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

1.20% (68th) EPSS

CVSS 4.3 · medium

Is it mine?

13 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · osv · nvd

EPSS · scored 2026-10-27

The X509Extension in pyOpenSSL before 0.13.1 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.

cvss

Technical severity, 0–10. One row per scoring source.

7.5

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · low–high · 3.7–7.5

v2.04.3mediumAV:N/AC:M/Au:N/C:N/I:P/A:Nprimary · NVD / NIST USexploitability 8.6 · impact 2.9

v2.03.7lowAV:N/AC:M/Au:N/C:N/I:P/A:N/E:Usecondary · CVSS-BT (t0sche)

v3.17.5highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:Nsecondary · OSV

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-20USprimaryCWE-20US

affected products (13)

Products and version ranges known to be affected.

n/a n/a≤ n/aenisa_euvdEU
canonical ubuntu linux= 10.04nvdUScpe:2.3:o:canonical:ubuntu_linux:*:*:*:*:*:*:*:*
canonical ubuntu linux= 12.04nvdUScpe:2.3:o:canonical:ubuntu_linux:*:*:*:*:*:*:*:*
canonical ubuntu linux= 12.10nvdUScpe:2.3:o:canonical:ubuntu_linux:*:*:*:*:*:*:*:*
canonical ubuntu linux= 13.04nvdUScpe:2.3:o:canonical:ubuntu_linux:*:*:*:*:*:*:*:*
jean-paul calderone pyopenssl≤ 0.13nvdUScpe:2.3:a:jean-paul_calderone:pyopenssl:*:*:*:*:*:*:*:*
jean-paul calderone pyopenssl= 0.10nvdUScpe:2.3:a:jean-paul_calderone:pyopenssl:*:*:*:*:*:*:*:*
jean-paul calderone pyopenssl= 0.11nvdUScpe:2.3:a:jean-paul_calderone:pyopenssl:*:*:*:*:*:*:*:*
jean-paul calderone pyopenssl= 0.12nvdUScpe:2.3:a:jean-paul_calderone:pyopenssl:*:*:*:*:*:*:*:*
jean-paul calderone pyopenssl= 0.7nvdUScpe:2.3:a:jean-paul_calderone:pyopenssl:*:*:*:*:*:*:*:*
jean-paul calderone pyopenssl= 0.8nvdUScpe:2.3:a:jean-paul_calderone:pyopenssl:*:*:*:*:*:*:*:*
jean-paul calderone pyopenssl= 0.9nvdUScpe:2.3:a:jean-paul_calderone:pyopenssl:*:*:*:*:*:*:*:*
PyPI pyopenssl< 0.13.1osvUSpkg:pypi/pyopenssl

advisories (2)

Vendor and ecosystem advisories describing this.

GHSA-6748-36qp-fx6rPyOpenSSL Mishandles NUL Byte In Certificate Subject Alternative Name2022-05-17ghsa · osvUS
The X509Extension in pyOpenSSL before 0.13.1 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.
PYSEC-2013-312013-09-30vendor · osvUS
The X509Extension in pyOpenSSL before 0.13.1 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.

also known as (6)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd osv nvd NVD CVE.org MITRE

published 2013-09-30modified 2026-06-16

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+25188 more

references (14)

External citations — patches, advisories, analysis.

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