Bug 1305437 (CVE-2016-2217)

Summary:	CVE-2016-2217 socat: Hard coded 1024 bit DH p parameter was not prime
Product:	[Other] Security Response	Reporter:	Adam Mariš <amaris>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED NOTABUG	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	abhgupta, dmcphers, jialiu, jokerman, kseifried, lmeyer, mmccomas, pwouters, tiwillia
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	socat 1.7.3.1, socat 2.0.0-b9	Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2016-02-08 09:18:22 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:
Bug Blocks:	1303890

Description Adam Mariš 2016-02-08 09:17:24 UTC

It was found that in the OpenSSL address implementation the hard coded 1024 bit DH p parameter was not prime. The effective cryptographic strength of a key exchange using these parameters was weaker than the one one could get by using a prime p, making easier for eavesdropper to recover the shared secret from a key exchange that uses them.

Affected versions are 1.7.3.0 and 2.0.0-b8.

CVE request:

http://seclists.org/oss-sec/2016/q1/261

Comment 1 Paul Wouters 2016-02-08 14:58:04 UTC

why was this closed again? It is a real bug for which there is a bug fix

Comment 2 Adam Mariš 2016-02-08 15:29:19 UTC

(In reply to Paul Wouters from comment #1)
> why was this closed again? It is a real bug for which there is a bug fix

Versions we ship are listed in advisory as not affected.

Comment 3 Tomas Hoger 2016-02-11 08:47:52 UTC

Upstream commit:

http://repo.or.cz/socat.git/commitdiff/eab3c89f2dc0df0d9638941891e8ab233dfb0611

The problematic 1024 bit DH param was introduced in this commit in version 1.7.3.0:

http://repo.or.cz/socat.git/commitdiff/281d1bd6515c2f0f8984fc168fb3d3b91c20bdc0

socat versions in Red Hat Enterprise Linux 7 and Fedora / EPEL are all 1.7.2.x, and hence use 512 bit DH params by default.  Of course, such short parameters are known to be too weak these days - see LOGJAM / bug 1223211 - and should be replaced.  We've had Red Hat Enterprise Linux 7 bug 1021946 open for that for a while now.  Users of socat can use dhparams or cert options for OPENSSL address type to make it use custom stronger DH parameters.

Upstream security advisory link follows.

External References:

http://www.dest-unreach.org/socat/contrib/socat-secadv7.html