A denial of service flaw was found in the way python-backports-ssl_match_hostname, an implementation that brings the ssl.match_hostname() function from Python 3.2 to users of earlier versions of Python, performed matching of the certificate's name in the case it contained many '*' wildcard characters. A remote attacker, able to obtain valid certificate with its name containing a lot of '*' wildcard characters, could use this flaw to cause denial of service (excessive CPU time consumption) by issuing request to validate that certificate for / in an application using the python-backports-ssl_match_hostname functionality. Upstream bug report: [1] http://bugs.python.org/issue17980 Acknowledgements: This issue was discovered by Florian Weimer of Red Hat Product Security Team.
This issue affects the versions of the python-backports-ssl_match_hostname package as shipped with Fedora release of 17, 18, and Fedora EPEL-6. Please schedule an update (once there is final upstream patch available).
Created python-backports-ssl_match_hostname tracking bugs for this issue Affects: fedora-all [bug 963187] Affects: epel-6 [bug 963188]
CVE request: http://www.openwall.com/lists/oss-security/2013/05/15/6 and Python 3.2 case follow-up: http://www.openwall.com/lists/oss-security/2013/05/15/7 (will file independent Python 3.2 bug shortly - after the lunch)
*** This bug has been marked as a duplicate of bug 963260 ***