Bug 663542 (CVE-2010-4347)

Summary:	CVE-2010-4347 kernel: local privilege escalation via /sys/kernel/debug/acpi/custom_method
Product:	[Other] Security Response	Reporter:	Eugene Teo (Security Response) <eteo>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	bhu, djorm, jkacur, lgoncalv, lwang, rt-maint, williams
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:	2013-03-11 03:11:40 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:	663543
Bug Blocks:

Description Eugene Teo (Security Response) 2010-12-16 05:47:40 UTC

Reported by Dave Jones, currently we have:

--w--w--w-. 1 root root 0 2010-11-11 14:56 /sys/kernel/debug/acpi/custom_method

which is just crazy. Change this to --w-------.

This custom_method file allows to inject custom ACPI methods into the ACPI interpreter tables. This control file was introduced with world writeable permissions in Linux Kernel 2.6.33.

Introduced in:
http://git.kernel.org/linus/a1a541d86f50a9957beeedb122a035870d602647
http://git.kernel.org/linus/a25ee9200eef07377e1703697afbb5d81f89e500

Fixed in:
http://git.kernel.org/linus/ed3aada1bf34c5a9e98af167f125f8a740fc726a

Comment 2 Eugene Teo (Security Response) 2010-12-16 06:01:34 UTC

Statement:

This issue did not affect the version of Linux kernel as shipped with Red Hat
Enterprise Linux 4, 5, and 6 as they did not include upstream commit a1a541d8 and a25ee920 that introduced the problem. This has been addressed in Red Hat Enterprise MRG via https://rhn.redhat.com/errata/RHSA-2011-0330.html.

Notes:

This requires debugfs to be mounted on a local system in order to have access to the custom_method file. Debugfs is not mounted by default. You need to run "mount -t debugfs nodev /sys/kernel/debug" as root first.

Comment 3 errata-xmlrpc 2011-03-10 20:04:58 UTC

This issue has been addressed in following products:

  MRG for RHEL-5

Via RHSA-2011:0330 https://rhn.redhat.com/errata/RHSA-2011-0330.html