Bug 749243 (CVE-2011-4080)

Summary:	CVE-2011-4080 kernel: sysctl: restrict write access to dmesg_restrict
Product:	[Other] Security Response	Reporter:	Petr Matousek <pmatouse>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	arozansk, bhu, dhoward, fhrbata, jkacur, jlieskov, jrieden, kernel-mgr, lgoncalv, lwang, nobody, plougher, rt-maint, vgoyal, 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:	2015-08-22 06:11:11 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:	749246, 749247, 749248, 749251, 749252, 749259, 761389
Bug Blocks:	740604

Description Petr Matousek 2011-10-26 14:54:19 UTC

When dmesg_restrict is set to 1 CAP_SYS_ADMIN is needed to read the kernel ring buffer.  But a root user without CAP_SYS_ADMIN is able to reset dmesg_restrict to 0.

This is an issue when e.g.  LXC (Linux Containers) are used and complete user space is running without CAP_SYS_ADMIN.  A unprivileged and jailed root user can bypass the dmesg_restrict protection.

Introduced by:
eaf06b241b091357e72b76863ba16e89610d31bd

Fixed by:
bfdc0b497faa82a0ba2f9dddcf109231dd519fcc

Comment 3 Petr Matousek 2011-10-26 15:04:53 UTC

Statement:

Red Hat Enterprise Linux 4 is now in Production 3 of the maintenance
life-cycle, https://access.redhat.com/support/policy/updates/errata/, therefore
the fix for this issue is not currently planned to be included in the future
updates. Future kernel updates in Red Hat Enterprise Linux 5, 6 and Red Hat Enterprise MRG may address this flaw.

Comment 4 Petr Matousek 2011-10-26 15:15:57 UTC

Created kernel tracking bugs for this issue

Affects: fedora-all [bug 749259]

Comment 5 Jan Lieskovsky 2011-10-27 09:13:26 UTC

The CVE identifier of CVE-2011-4080 has been assigned to this issue:
[1] http://www.openwall.com/lists/oss-security/2011/10/26/10

Comment 6 Eugene Teo (Security Response) 2011-10-28 03:54:36 UTC

(In reply to comment #5)
> The CVE identifier of CVE-2011-4080 has been assigned to this issue:
> [1] http://www.openwall.com/lists/oss-security/2011/10/26/10

And rejected. Removed CVE from the bugs.

Comment 7 Vincent Danen 2015-08-22 06:11:11 UTC

This was fixed in RHSA-2012:0481 and RHBA-2012:0361.

https://rhn.redhat.com/errata/RHBA-2012-0361.html (RHEL 5)
https://rhn.redhat.com/errata/RHSA-2012-0481.html (RHEL 6)