medium
5
CWE
416 415
Advisory Published
CVE Published
Updated

CVE-2015-6251: Use After Free

First published: Mon Aug 10 2015(Updated: )

A use-after-free flaw was found in GnuTLS's _gnutls_x509_dn_to_string() function. A remote attacker could create a specially crafted certificate with very long DistinguishedName (DN) entries that, when processed by an application compiled against GnuTLS, could cause that application to crash. This issue was fixed in upstream versions 3.4.4 and 3.3.17 of GnuTLS: <a href="https://lists.gnupg.org/pipermail/gnutls-devel/2015-August/007707.html">https://lists.gnupg.org/pipermail/gnutls-devel/2015-August/007707.html</a> <a href="https://lists.gnupg.org/pipermail/gnutls-devel/2015-August/007708.html">https://lists.gnupg.org/pipermail/gnutls-devel/2015-August/007708.html</a> The following patch fixes this issue: <a href="https://gitlab.com/gnutls/gnutls/commit/272854367efc130fbd4f1a51840d80c630214e12">https://gitlab.com/gnutls/gnutls/commit/272854367efc130fbd4f1a51840d80c630214e12</a> The affected function, _gnutls_x509_dn_to_string(), was first introduced in version 3.1.10 via commit: <a href="https://gitlab.com/gnutls/gnutls/commit/6be35136333b5d6289f23209cf896e741462909a">https://gitlab.com/gnutls/gnutls/commit/6be35136333b5d6289f23209cf896e741462909a</a> The gnutls packages in Red Hat Enterprise Linux 6 and earlier include GnuTLS versions 2.x or 1.x and are therefore not affected by this issue. External References: <a href="http://www.gnutls.org/security.html#GNUTLS-SA-2015-3">http://www.gnutls.org/security.html#GNUTLS-SA-2015-3</a>

Credit: secalert@redhat.com

Affected SoftwareAffected VersionHow to fix
redhat/gnutls<3.4.4
3.4.4
redhat/gnutls<3.3.17
3.3.17
GNU GnuTLS=3.3.0
GNU GnuTLS=3.3.0-pre0
GNU GnuTLS=3.3.1
GNU GnuTLS=3.3.2
GNU GnuTLS=3.3.3
GNU GnuTLS=3.3.4
GNU GnuTLS=3.3.5
GNU GnuTLS=3.3.6
GNU GnuTLS=3.3.7
GNU GnuTLS=3.3.8
GNU GnuTLS=3.3.9
GNU GnuTLS=3.3.10
GNU GnuTLS=3.3.11
GNU GnuTLS=3.3.12
GNU GnuTLS=3.3.13
GNU GnuTLS=3.3.14
GNU GnuTLS=3.3.15
GNU GnuTLS=3.3.16
GNU GnuTLS=3.4.0
GNU GnuTLS=3.4.1
GNU GnuTLS=3.4.2
GNU GnuTLS=3.4.3
Debian Debian Linux=8.0

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Frequently Asked Questions

  • What is the severity of CVE-2015-6251?

    CVE-2015-6251 has a medium severity rating, as it can lead to a denial of service by crashing the application.

  • How do I fix CVE-2015-6251?

    To fix CVE-2015-6251, upgrade GnuTLS to version 3.4.4 or later, or version 3.3.17 or later.

  • Which versions of GnuTLS are affected by CVE-2015-6251?

    CVE-2015-6251 affects GnuTLS versions prior to 3.4.4 and 3.3.17.

  • What can an attacker do with CVE-2015-6251?

    An attacker can exploit CVE-2015-6251 by sending a specially crafted certificate to an application using GnuTLS, causing it to crash.

  • How can I determine if my application is vulnerable to CVE-2015-6251?

    Check the version of GnuTLS linked to your application; if it's older than 3.4.4 or 3.3.17, it is vulnerable to CVE-2015-6251.

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