high
7.5
CWE
20
Advisory Published
CVE Published
Advisory Published
Updated

CVE-2013-4314: Input Validation

First published: Fri Sep 06 2013(Updated: )

The pyOpenSSL module implements hostname identity checks but it did not properly handle hostnames in the certificate that contain null bytes. In all releases prior to 0.13.1, the string formatting of subjectAltName X509Extension instances incorrectly truncated fields of the name when encountering the null byte. When a CA than an SSL client trusts issues a server certificate that has a null byte in the subjectAltName, remote attackers can obtain a certifcate for 'www.foo.org\0.example.com' from the CA to spoof 'www.foo.org' and conduct man-in-the-middle attacks between the pyOpenSSL-using client and SSL servers. [1] <a href="https://mail.python.org/pipermail/pyopenssl-users/2013-September/000478.html">https://mail.python.org/pipermail/pyopenssl-users/2013-September/000478.html</a>

Credit: secalert@redhat.com secalert@redhat.com

Affected SoftwareAffected VersionHow to fix
redhat/pyOpenSSL<0.13.1
0.13.1
pip/pyOpenSSL<0.13.1
0.13.1
pyOpenSSL<=0.13
pyOpenSSL=0.7
pyOpenSSL=0.8-a1
pyOpenSSL=0.9
pyOpenSSL=0.10
pyOpenSSL=0.11
pyOpenSSL=0.11-a1
pyOpenSSL=0.11-a2
pyOpenSSL=0.12
Ubuntu Linux=10.04
Ubuntu Linux=12.04
Ubuntu Linux=12.10
Ubuntu Linux=13.04
Ubuntu=10.04
Ubuntu=12.04
Ubuntu=12.10
Ubuntu=13.04

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Reference Links

Frequently Asked Questions

  • What is the severity of CVE-2013-4314?

    CVE-2013-4314 is classified as a moderate severity vulnerability.

  • How do I fix CVE-2013-4314?

    To fix CVE-2013-4314, upgrade pyOpenSSL to version 0.13.1 or later.

  • Which versions of pyOpenSSL are affected by CVE-2013-4314?

    CVE-2013-4314 affects all versions of pyOpenSSL prior to 0.13.1.

  • What kind of vulnerability is CVE-2013-4314?

    CVE-2013-4314 involves improper handling of hostnames containing null bytes in the pyOpenSSL module.

  • Is there a patch available for CVE-2013-4314?

    Yes, a patch is available by upgrading pyOpenSSL to version 0.13.1.

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