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CVE-2013-4314

PyOpenSSL Mishandles NUL Byte In Certificate Subject Alternative Name

4.3 MediumFix available

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.

Exploit likelihood

1.20%Up 0.1 points since Feb 4, 2022
90%50%10%1%

What each source reports

NVD Score used 4.3

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.

Record
CVE-2013-4314
CVSS 2.0
4.3 MediumAV:N/AC:M/Au:N/C:N/I:P/A:N
Weakness
CWE-20
Updated
2026-11-02
CVE List No score

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.

Record
CVE-2013-4314
Updated
2026-11-02
EUVDEUVD-2013-0029 No score

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.

Record
EUVD-2013-0029
Updated
2026-11-03
GitHub AdvisoriesGHSA-6748-36qp-fx6r 8.7

PyOpenSSL Mishandles NUL Byte In Certificate Subject Alternative Name

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.

Record
GHSA-6748-36qp-fx6r
CVSS 4.0
8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
CVSS 3.1
7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Weakness
CWE-20
Updated
2026-11-02
OSVGHSA-6748-36qp-fx6r 8.7

PyOpenSSL Mishandles NUL Byte In Certificate Subject Alternative Name

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.

Record
GHSA-6748-36qp-fx6r
CVSS 4.0
8.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
CVSS 3.1
7.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Weakness
CWE-20
Updated
2026-11-02
OSV No score

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.

Record
CVE-2013-4314
Updated
2026-11-02
Show 9 moreShow less
OSVDEBIAN-CVE-2013-4314 No score

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.

Record
DEBIAN-CVE-2013-4314
Updated
2026-11-02
OSVMGASA-2013-0277 No score

Updated python-OpenSSL package fixes security vulnerability

The string formatting of subjectAltName X509Extension instances in pyOpenSSL before 0.13.1 incorrectly truncated fields of the name when encountering a null byte, possibly allowing man-in-the-middle attacks through certificate spoofing (CVE-2013-4314).

Record
MGASA-2013-0277
Updated
2026-11-02
OSVopenSUSE-SU-2024:10214-1 No score

python-pyOpenSSL-16.2.0-1.3 on GA media

These are all security issues fixed in the python-pyOpenSSL-16.2.0-1.3 package on the GA media of openSUSE Tumbleweed.

Record
openSUSE-SU-2024:10214-1
Updated
2026-11-02
OSVopenSUSE-SU-2024:11253-1 No score

python36-pyOpenSSL-20.0.1-1.4 on GA media

These are all security issues fixed in the python36-pyOpenSSL-20.0.1-1.4 package on the GA media of openSUSE Tumbleweed.

Record
openSUSE-SU-2024:11253-1
Updated
2026-11-02
OSVopenSUSE-SU-2024:14154-1 No score

python310-pyOpenSSL-24.1.0-1.2 on GA media

These are all security issues fixed in the python310-pyOpenSSL-24.1.0-1.2 package on the GA media of openSUSE Tumbleweed.

Record
openSUSE-SU-2024:14154-1
Updated
2026-11-02
OSVopenSUSE-SU-2026:11470-1 No score

python313-pyOpenSSL-26.4.0-1.1 on GA media

These are all security issues fixed in the python313-pyOpenSSL-26.4.0-1.1 package on the GA media of openSUSE Tumbleweed.

Record
openSUSE-SU-2026:11470-1
Updated
2026-11-02
OSVPYSEC-2013-31 No score

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.

Record
PYSEC-2013-31
Updated
2026-11-02
OSVSUSE-FU-2022:0444-1 No score

Feature update for venv-salt-minion

This feature update for venv-salt-minion provides the following changes:

  • Introduce venv-salt-minion.
  • Track already fixed issues.
Record
SUSE-FU-2022:0444-1
Updated
2026-11-02
OSVSUSE-FU-2022:0445-1 No score

Feature update for venv-salt-minion

This feature update for venv-salt-minion provides the following changes:

  • Introduce venv-salt-minion.
  • Mention fixed issues provided with the bundle.
Record
SUSE-FU-2022:0445-1
Updated
2026-11-02

Affected products

Affected packages

Affected packages
PackageAffectedFixed
pyopenssl
PyPI
before 0.13.1
0.13.1
pyopenssl
Debian:12
before 0.13-2.1
0.13-2.1
pyopenssl
Debian:13
before 0.13-2.1
0.13-2.1
pyopenssl
Debian:14
before 0.13-2.1
0.13-2.1
pyopenssl
Debian:6.0
before 0.10-1+squeeze1, plus listed versions
0.10-1
0.10-1+squeeze1
pyopenssl
Debian:7
before 0.13-2+deb7u1, plus listed versions
0.13-2
0.13-2+deb7u1
pyopenssl
PyPI
before 0.13.1, plus listed versions
0.100.110.120.130.60.70.80.9
0.13.1
python-OpenSSL
Mageia:2
before 0.12-1.1.mga2
0.12-1.1.mga2
python-OpenSSL
Mageia:3
before 0.13-2.1.mga3
0.13-2.1.mga3
python-pyOpenSSL
openSUSE:Tumbleweed
before 24.1.0-1.2
24.1.0-1.2
python-pyOpenSSL
openSUSE:Tumbleweed
before 26.4.0-1.1
26.4.0-1.1

History

History
RecordedChangedSources
facts
aliasesEUVD
first indexedCVE List, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2013-4314 is a medium vulnerability (CVSS 4.3) in Jean-paul Calderone Pyopenssl, published September 13, 2013. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.20%, the 68th percentile. Fixed in pyopenssl 0.13.1.

References

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