medium
4.3
CWE
20
Advisory Published
CVE Published
Updated

CVE-2013-4238: Input Validation

First published: Tue Aug 13 2013(Updated: )

A flaw was found in the way ssl.match_hostname() from the Python SSL module checked the hostname's identity when handling certificates that contain hostnames with NULL bytes. An attacker could potentially exploit this flaw to conduct man-in-the-middle attacks to spoof SSL servers. Note that to exploit this issue, an attacker would need to obtain a carefully-crafted certificate signed by an authority that the client trusts. References: <a href="http://bugs.python.org/issue18709">http://bugs.python.org/issue18709</a> <a href="http://bugs.python.org/file31241/CVE-2013-4073_py34.patch">http://bugs.python.org/file31241/CVE-2013-4073_py34.patch</a> <a href="http://bugs.python.org/file31242/CVE-2013-4073_py33.patch">http://bugs.python.org/file31242/CVE-2013-4073_py33.patch</a> <a href="http://bugs.python.org/file31243/CVE-2013-4073_py27.patch">http://bugs.python.org/file31243/CVE-2013-4073_py27.patch</a>

Credit: secalert@redhat.com

Affected SoftwareAffected VersionHow to fix
Ubuntu=10.04
Python 2.7=2.6.1
Python 2.7=2.6.2
Python 2.7=2.6.3
Python 2.7=2.6.4
Python 2.7=2.6.5
Python 2.7=2.6.6
Python 2.7=2.6.7
Python 2.7=2.6.8
Python 2.7=2.6.2150
Python 2.7=2.6.6150
Python 2.7=2.7.1
Python 2.7=2.7.1-rc1
Python 2.7=2.7.2-rc1
Python 2.7=2.7.3
Python 2.7=2.7.1150
Python 2.7=2.7.1150
Python 2.7=2.7.2150
Python 2.7=3.0
Python 2.7=3.0.1
Python 2.7=3.1
Python 2.7=3.1.1
Python 2.7=3.1.2
Python 2.7=3.1.3
Python 2.7=3.1.4
Python 2.7=3.1.5
Python 2.7=3.1.2150
Python 2.7=3.2
Python 2.7=3.2-alpha
Python 2.7=3.2.3
Python 2.7=3.2.2150
Python 2.7=3.3
Python 2.7=3.3-beta2
Python 2.7=3.4-alpha1
SUSE Linux=11.4
SUSE Linux=12.2
SUSE Linux=12.3

Remedy

http://bugs.python.org/issue18709

Remedy

https://bugzilla.redhat.com/show_bug.cgi?id=996381

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Reference Links

Frequently Asked Questions

  • What is the severity of CVE-2013-4238?

    CVE-2013-4238 has a moderate severity level due to the potential for man-in-the-middle attacks.

  • How do I fix CVE-2013-4238?

    To fix CVE-2013-4238, upgrade to a version of Python where the vulnerability has been patched.

  • Which versions of Python are affected by CVE-2013-4238?

    CVE-2013-4238 affects multiple versions of Python, including 2.6.1 through 3.4 and several Ubuntu versions.

  • What kind of attacks can CVE-2013-4238 be exploited for?

    CVE-2013-4238 can be exploited to carry out man-in-the-middle attacks, allowing attackers to spoof SSL servers.

  • Is CVE-2013-4238 related to SSL certificate validation?

    Yes, CVE-2013-4238 is specifically related to how ssl.match_hostname() validates SSL certificate hostnames.

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