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Bug 1180239 (CVE-2015-0205)

Summary:	CVE-2015-0205 openssl: DH client certificates accepted without verification
Product:	[Other] Security Response	Reporter:	Vasyl Kaigorodov <vkaigoro>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	carnil, cdewolf, chrisw, dandread, darran.lofthouse, erich, grocha, jason.greene, jawilson, jclere, jdoyle, john.haxby, lgao, myarboro, nlevinki, oguzyilmaz, pslavice, rfortier, rhs-bugs, rsvoboda, vtunka, weli
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	OpenSSL 1.0.1k, OpenSSL 1.0.0p	Doc Type:	Bug Fix
Doc Text:	It was found that an OpenSSL server would, under certain conditions, accept Diffie-Hellman client certificates without the use of a private key. An attacker could use a user's client certificate to authenticate as that user, without needing the private key.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2021-10-20 10:48:54 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	1181013, 1181015, 1181016, 1181017, 1181018
Bug Blocks:

Description Vasyl Kaigorodov 2015-01-08 16:57:47 UTC

OpenSSL released security advisory [1] which fixes the below issue:

An OpenSSL server will accept a DH certificate for client authentication
without the certificate verify message. This effectively allows a client
to authenticate without the use of a private key. This only affects servers
which trust a client certificate authority which issues certificates
containing DH keys: these are extremely rare and hardly ever encountered.

[1]: https://www.openssl.org/news/secadv_20150108.txt

Comment 1 Vincent Danen 2015-01-08 18:33:44 UTC

Upstream commit that looks to fix the problem:

https://github.com/openssl/openssl/commit/1421e0c584ae9120ca1b88098f13d6d2e90b83a3


External References:

https://www.openssl.org/news/secadv_20150108.txt

Comment 2 Huzaifa S. Sidhpurwala 2015-01-12 08:29:46 UTC

Created openssl tracking bugs for this issue:

Affects: fedora-all [bug 1181013]

Comment 4 Fedora Update System 2015-01-13 00:02:36 UTC

openssl-1.0.1k-1.fc21 has been pushed to the Fedora 21 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 5 Huzaifa S. Sidhpurwala 2015-01-16 04:15:04 UTC

Statement:

This issue does not affect the version of openssl and openssl097a as shipped with Red Hat Enterprise Linux 5. This issue does not affect the version of openssl098e as shipped with Red Hat Enterprise Linux 6 and 7.

Comment 6 Fedora Update System 2015-01-20 21:06:01 UTC

openssl-1.0.1e-41.fc20 has been pushed to the Fedora 20 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 7 errata-xmlrpc 2015-01-21 21:29:11 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 6
  Red Hat Enterprise Linux 7

Via RHSA-2015:0066 https://rhn.redhat.com/errata/RHSA-2015-0066.html