oss-sec mailing list archives
Re: CVE Request (minor) -- python-backports-ssl_match_hostname: Denial of service when matching certificate with many '*' wildcard characters
From: Kurt Seifried <kseifried () redhat com>
Date: Wed, 15 May 2013 19:51:21 -0600
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 05/15/2013 05:19 AM, Jan Lieskovsky wrote:
Hello Kurt, Steve, vendors, 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 (no patch yet): [1] http://bugs.python.org/issue17980 References: [2] https://bugzilla.redhat.com/show_bug.cgi?id=963186 Credit: Issue was found by Florian Weimer of Red Hat Product Security Team Could you allocate a CVE identifier for this (it's possible that Python 3.2 implementation is vulnerable to the same problem too, will check that case yet)? Thank you && Regards, Jan. -- Jan iankko Lieskovsky / Red Hat Security Response Team -- [*] Would be minor issue because ability to obtain such valid certificate would mean the necessity to use some compromised CA. On the other hand though being corner case, can't be completely excluded.
Please use CVE-2013-2098 for this issue. - -- Kurt Seifried Red Hat Security Response Team (SRT) PGP: 0x5E267993 A90B F995 7350 148F 66BF 7554 160D 4553 5E26 7993 -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.13 (GNU/Linux) iQIcBAEBAgAGBQJRlDuZAAoJEBYNRVNeJnmTrLEP/30fUBUGtPgQp/vyE8InM20c 27ctbuHVRkAFxNGgDHVXsEysEMb2IwOK2IDLFHyv9E62M83FWPrdaT+ub95wXriW jI3SzZfyVqnK3nu1fLsydOUv3+MzOo2CzSreJ0M0p7Iy4erp94iR0O3g0OeOhoVe it9a77Wgb8PAVYNGqpO0zqMyC/H4X1S+IdFS/lq2YKe+RpdV79dL1TWNMXo/spWd UZWxMdeSibNwtNw8K+g/QMdT0IbTDjNIJa5ncSjfA5tt6wmwrQ1+3VfxNBrQLrZK 0tpJIcjh8G0c6/nzXoonvTTv531THk1NZpe+7jNKA6bcI48eCRykBrTzwVwqBOpY jDu+ZeijGwaPC1r+2IRHsfpzJCHMGuirZWIusAJYU/fwHk/OUIPn+cEUSyp24zpU 6c6YCyMoHu8w9PHAeLGP1TVY5AuNKxWH56dWfCpfYo5egrdF+Hbg+Wxkc3C9dYMv eEFB/XZZ1ZQYJTcOdvrRNcP6zcw7RKjVfunAsevR72r7s2QiNiJ1u+luhp5NFw19 5YAcFlm9MUD408UigqjGzwA3DjN4+qEa+E/CPuftH+uvXAWNnG3Ngyx4eNKq8mtz QnA2aeP2OiNq92kJueNnU+z3j+HQMn5J8UnWKXuJgQcaulxAfMn+W7VG6p14T/r/ v68SLazxWV41c3I9Kl95 =DuLR -----END PGP SIGNATURE-----
Current thread:
- CVE Request (minor) -- python-backports-ssl_match_hostname: Denial of service when matching certificate with many '*' wildcard characters Jan Lieskovsky (May 15)
- CVE Request (minor) -- Python 3.2: DoS when matching certificate with many '*' wildcard characters {was: [oss-security] CVE Request (minor) -- python-backports-ssl_match_hostname: Denial of service when matching certificate with many '*' wildcard characters } Jan Lieskovsky (May 15)
- Re: CVE Request (minor) -- Python 3.2: DoS when matching certificate with many '*' wildcard characters {was: [oss-security] CVE Request (minor) -- python-backports-ssl_match_hostname: Denial of service when matching certificate with many '*' wildcard characters } Kurt Seifried (May 15)
- Re: CVE Request (minor) -- Python 3.2: DoS when matching certificate with many '*' wildcard characters {was: [oss-security] CVE Request (minor) -- python-backports-ssl_match_hostname: Denial of service when matching certificate with many '*' wildcard characters } Tomas Hoger (May 20)
- Re: CVE Request (minor) -- Python 3.2: DoS when matching certificate with many '*' wildcard characters {was: [oss-security] CVE Request (minor) -- python-backports-ssl_match_hostname: Denial of service when matching certificate with many '*' wildcard characters } Kurt Seifried (May 22)
- Re: CVE Request (minor) -- Python 3.2: DoS when matching certificate with many '*' wildcard characters {was: [oss-security] CVE Request (minor) -- python-backports-ssl_match_hostname: Denial of service when matching certificate with many '*' wildcard characters } Tomas Hoger (May 23)
- Re: CVE Request (minor) -- Python 3.2: DoS when matching certificate with many '*' wildcard characters {was: [oss-security] CVE Request (minor) -- python-backports-ssl_match_hostname: Denial of service when matching certificate with many '*' wildcard characters } Kurt Seifried (May 15)
- CVE Request (minor) -- Python 3.2: DoS when matching certificate with many '*' wildcard characters {was: [oss-security] CVE Request (minor) -- python-backports-ssl_match_hostname: Denial of service when matching certificate with many '*' wildcard characters } Jan Lieskovsky (May 15)