Bug 1202410 (CVE-2015-0285)

Summary:	CVE-2015-0285 openssl: handshake with unseeded PRNG
Product:	[Other] Security Response	Reporter:	Martin Prpič <mprpic>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED NOTABUG	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	aavati, acathrow, alonbl, bazulay, bmcclain, cdewolf, cfergeau, dandread, darran.lofthouse, dblechte, dknox, ecohen, erik-fedora, gklein, idith, iheim, jason.greene, jawilson, jboss-set, jclere, jdoyle, ktietz, lfarkas, lgao, lsurette, marcandre.lureau, mehmetgelisin, michal.skrivanek, myarboro, nlevinki, pgier, pslavice, rbalakri, rfortier, rhs-bugs, rh-spice-bugs, rjones, rsvoboda, security-response-team, sgirijan, smohan, ssaha, tmraz, twalsh, vbellur, vtunka, weli, yeylon
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	openssl 1.0.2a	Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2015-03-18 03:38:40 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:	1202442

Description Martin Prpič 2015-03-16 14:48:46 UTC

Under certain conditions an OpenSSL 1.0.2 client can complete a handshake with an unseeded PRNG. The conditions are:

- The client is on a platform where the PRNG has not been seeded automatically, and the user has not seeded manually

- A protocol specific client method version has been used (i.e. not SSL_client_methodv23)

- A ciphersuite is used that does not require additional random data from the PRNG beyond the initial ClientHello client random (e.g. PSK-RC4-SHA).

If the handshake succeeds then the client random that has been used will have
been generated from a PRNG with insufficient entropy and therefore the output
may be predictable.

For example using the following command with an unseeded openssl will succeed on an unpatched platform:

openssl s_client -psk 1a2b3c4d -tls1_2 -cipher PSK-RC4-SHA

This issue affects OpenSSL version 1.0.2, and is fixed in version 1.0.2a.

Upstream patch:

https://git.openssl.org/gitweb/?p=openssl.git;a=commit;h=e1b568dd2462f7cacf98f3d117936c34e2849a6b

Acknowledgements:

Red Hat would like to thank the OpenSSL project for reporting this issue. Upstream acknowledges Matt Caswell of the OpenSSL development team as the original reporter.

Comment 1 Huzaifa S. Sidhpurwala 2015-03-18 03:37:59 UTC

Statement:

This issue did not affect the versions of openssl as shipped with Red Hat Enterprise Linux 5, 6, and 7.

Comment 2 Martin Prpič 2015-03-19 14:35:06 UTC

External References:

https://openssl.org/news/secadv_20150319.txt
https://access.redhat.com/articles/1384453