Bug 1115576 (CVE-2014-3537)

Summary:	CVE-2014-3537 cups: insufficient checking leads to privilege escalation
Product:	[Other] Security Response	Reporter:	Francisco Alonso <falonso>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	bressers, carnil, jpopelka, jrusnack, security-response-team, twaugh
Target Milestone:	---	Keywords:	Patch, Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:	It was discovered that CUPS allowed certain users to create symbolic links in certain directories under /var/cache/cups/. A local user with the 'lp' group privileges could use this flaw to read the contents of arbitrary files on the system or, potentially, escalate their privileges on the system.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2015-03-26 21:43:39 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:	1117794, 1118263, 1119303
Bug Blocks:	1101912, 1115577

Description Francisco Alonso 2014-07-02 16:07:26 UTC

It was discovered that a local user with privileges of group=lp can write symbolic links in the rss directory and use that to gain '@SYSTEM' group privilege with cupsd.

Permissions:

drwxrwxr-x.  2 root lp   4096 Jul  2 09:58 /var/cache/cups/rss

SELinux mitigates this vulnerability

Comment 1 Francisco Alonso 2014-07-02 16:13:27 UTC

Acknowledgment:

This issue was discovered by Francisco Alonso of the Red Hat Security Response Team.

Comment 7 Francisco Alonso 2014-07-10 09:16:41 UTC

Statement:

This issue is not planned to be fixed in Red Hat Enterprise Linux 5 as it is now in Production 3 Phase of the support and maintenance life cycle, https://access.redhat.com/support/policy/updates/errata/

Comment 9 Francisco Alonso 2014-07-14 13:19:17 UTC

Patch for symlink: https://cups.org/strfiles.php/3363/str4450.patch
Fixed In: 2.0-current (SVN: r11993)

References:

http://www.cups.org/blog.php?L724
https://cups.org/str.php?L4450

Comment 10 Francisco Alonso 2014-07-14 13:20:35 UTC

Created cups tracking bugs for this issue:

Affects: fedora-all [bug 1119303]

Comment 11 Fedora Update System 2014-07-19 06:00:33 UTC

cups-1.7.4-1.fc20 has been pushed to the Fedora 20 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 14 Francisco Alonso 2014-08-11 14:37:51 UTC

This fix is insufficient, the additional check can be easily bypassed if language[0] is NULL. The CVE-2014-5029 id has been assigned for the incomplete fix.

http://seclists.org/oss-sec/2014/q3/209

Comment 15 Tomas Hoger 2014-08-11 18:32:53 UTC

The incomplete fix CVE-2014-5029 is tracked via bug 1122600.

Comment 16 Fedora Update System 2014-10-03 03:57:09 UTC

cups-1.6.4-10.fc19 has been pushed to the Fedora 19 stable repository.  If problems still persist, please make note of it in this bug report.

Comment 17 Martin Prpič 2014-10-07 08:44:55 UTC

IssueDescription:

It was discovered that CUPS allowed certain users to create symbolic links in certain directories under /var/cache/cups/. A local user with the 'lp' group privileges could use this flaw to read the contents of arbitrary files on the system or, potentially, escalate their privileges on the system.

Comment 18 errata-xmlrpc 2014-10-14 07:31:42 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 6

Via RHSA-2014:1388 https://rhn.redhat.com/errata/RHSA-2014-1388.html

Comment 19 Tomas Hoger 2015-03-26 21:43:39 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHBA-2015:0386 https://rhn.redhat.com/errata/RHBA-2015-0386.html