Bug 1010137 (CVE-2013-4351)

Summary:	CVE-2013-4351 gnupg: treats no-usage-permitted keys as all-usages-permitted
Product:	[Other] Security Response	Reporter:	Ratul Gupta <ratulg>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	bcl, btotty, huzaifas, jjaburek, jkurik, rdieter, tmraz
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2015-08-22 06:26:37 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:	1010140, 1010141, 1010142, 1015736, 1015737, 1015738, 1015739, 1015740, 1015741, 1015743, 1018109, 1018110
Bug Blocks:	1010144, 1015687

Description Ratul Gupta 2013-09-20 05:20:21 UTC

GnuPG and GnuPG2 are found to have a flaw, where the key flags are misinterpreted, which could possibly lead to a breach of confidentiality or a mistaken identity verification. Key flags are the packets, that indicated the capabilities of the key, represented as binary flags. The issue is that if a key or subkey has this "key flags" subpacket attached with all bits cleared (off), GnuPG currently treats the key as having all bits set (on), though the thing to note is that the keys with this sort of marker are very rare in the wild.
The risks are unlikely today, and they are not particularly dangerous, but the keyholder's stated intent of separating out keys by context of use is being ignored, so there is a window of vulnerability that should not be open.

References:
http://seclists.org/oss-sec/2013/q3/599
https://bugs.gentoo.org/show_bug.cgi?id=484836
https://bugzilla.novell.com/show_bug.cgi?id=840510

Comment 1 Ratul Gupta 2013-09-20 05:28:41 UTC

Patches are available, but appear to only be applied on the development
branch (2.1.x).  So stable branches 1.4.x and 2.0.x remain vulnerable at
the moment.

Comment 2 Ratul Gupta 2013-09-20 05:31:39 UTC

Created gnupg2 tracking bugs for this issue:

Affects: fedora-all [bug 1010141]
Affects: epel-5 [bug 1010142]

Comment 3 Ratul Gupta 2013-09-20 05:31:57 UTC

Created gnupg tracking bugs for this issue:

Affects: fedora-all [bug 1010140]

Comment 4 Fedora Update System 2013-10-10 14:47:56 UTC

gnupg-1.4.15-1.fc20 has been pushed to the Fedora 20 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 5 Huzaifa S. Sidhpurwala 2013-10-11 09:13:46 UTC

Upstream patch:

http://git.gnupg.org/cgi-bin/gitweb.cgi?p=gnupg.git;a=commitdiff;h=4bde12206c5bf199dc6e12a74af8da4558ba41bf

Comment 8 Fedora Update System 2013-10-12 00:02:46 UTC

gnupg-1.4.15-1.fc19 has been pushed to the Fedora 19 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 13 errata-xmlrpc 2013-10-24 15:25:02 UTC

This issue has been addressed in following products:

  Red Hat Enterprise Linux 5
  Red Hat Enterprise Linux 6

Via RHSA-2013:1459 https://rhn.redhat.com/errata/RHSA-2013-1459.html

Comment 14 errata-xmlrpc 2013-10-24 15:27:08 UTC

This issue has been addressed in following products:

  Red Hat Enterprise Linux 5

Via RHSA-2013:1458 https://rhn.redhat.com/errata/RHSA-2013-1458.html

Comment 15 Fedora Update System 2013-11-13 02:26:12 UTC

gnupg-1.4.15-1.fc18 has been pushed to the Fedora 18 stable repository.  If problems still persist, please make note of it in this bug report.