Bug 1362016 (CVE-2016-6489)

Summary:	CVE-2016-6489 nettle: RSA/DSA code is vulnerable to cache-timing related attacks
Product:	[Other] Security Response	Reporter:	Huzaifa S. Sidhpurwala <huzaifas>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	cperry, dwmw2, huzaifas, klember, mike, nmavrogi, pwouters, slawomir, szidek, tmraz
Target Milestone:	---	Keywords:	Reopened, Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:	It was found that nettle's RSA and DSA decryption code was vulnerable to cache-related side channel attacks. An attacker could use this flaw to recover the private key from a co-located virtual-machine instance.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2019-07-12 13:04:19 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:	1362017, 1362018, 1362020, 1362021, 1362022, 1364897, 1429958, 1429959
Bug Blocks:	1323912

Description Huzaifa S. Sidhpurwala 2016-08-01 07:55:45 UTC

A cache-related side channel was found in nettle's RSA and DSA decryption code. An attacker could use this flaw to recover the private key, from a co-located virtual-machine instance.


References:

https://eprint.iacr.org/2016/596.pdf
https://git.lysator.liu.se/nettle/nettle/commit/3fe1d6549765ecfb24f0b80b2ed086fdc818bff3

Comment 1 Huzaifa S. Sidhpurwala 2016-08-01 07:56:51 UTC

Created nettle tracking bugs for this issue:

Affects: fedora-all [bug 1362017]
Affects: epel-5 [bug 1362021]

Comment 2 Huzaifa S. Sidhpurwala 2016-08-01 07:56:59 UTC

Created mingw-nettle tracking bugs for this issue:

Affects: fedora-all [bug 1362018]
Affects: epel-7 [bug 1362022]

Comment 3 Huzaifa S. Sidhpurwala 2016-08-01 07:57:04 UTC

Created compat-nettle27 tracking bugs for this issue:

Affects: fedora-23 [bug 1362020]

Comment 4 Huzaifa S. Sidhpurwala 2016-08-01 07:59:23 UTC

Note:

As per: http://seclists.org/oss-sec/2016/q3/206 , the upstream fix has "some unintended side effects" and needs to be reviewed before being applied.

Comment 6 Nikos Mavrogiannopoulos 2016-08-08 07:36:47 UTC

The upstream author has included sanity checks at the functions using mpz_powm_sec() to prevent crashes by invalid private keys. As such, the unintended side-effects are no longer the case.

https://git.lysator.liu.se/nettle/nettle/commit/52b9223126b3f997c00d399166c006ae28669068

Comment 7 errata-xmlrpc 2016-11-03 19:31:30 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2016:2582 https://rhn.redhat.com/errata/RHSA-2016-2582.html

Comment 16 Product Security DevOps Team 2019-07-12 13:04:19 UTC

This bug is now closed. Further updates for individual products will be reflected on the CVE page(s):

https://access.redhat.com/security/cve/cve-2016-6489