Bug 689337 (CVE-2011-2534)

Summary:	CVE-2011-2534 ipv4: netfilter: ipt_CLUSTERIP: fix buffer overflow
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:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	arozansk, bhu, dhoward, jkacur, jlieskov, kernel-mgr, kmcmartin, lgoncalv, lwang, mjc, pfrields, rkhan, rt-maint, tcallawa, vkrizan, 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:	2015-07-29 14:13:37 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:	689339, 689340, 689341, 689342, 689343
Bug Blocks:

Description Eugene Teo (Security Response) 2011-03-21 06:57:54 UTC

'buffer' string is copied from userspace.  It is not checked whether it is zero terminated.  This may lead to overflow inside of simple_strtoul().  Changli Gao suggested to copy not more than user supplied 'size' bytes.  

It was introduced before the git epoch.  Files "ipt_CLUSTERIP/*" are root writable only by default, however, on some setups permissions might be relaxed to e.g. network admin user.

http://marc.info/?l=netfilter-devel&m=130036157327564&w=2

Proposed patch:
http://git.kernel.org/?p=linux/kernel/git/kaber/nf-2.6.git;a=commitdiff;h=961ed183a9fd080cf306c659b8736007e44065a5

Acknowledgements:

Red Hat would like to thank Vasiliy Kulikov of Openwall for reporting this issue.

Comment 3 Jiri Pirko 2011-03-25 13:32:03 UTC

http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=961ed183a9fd080cf306c659b8736007e44065a5

Comment 4 Eugene Teo (Security Response) 2011-04-11 03:45:03 UTC

Didn't assign a CVE name for this one as the default perms for this is S_IWUSR|S_IRUSR. But MITRE might assign one.

Comment 5 Jan Lieskovsky 2011-06-23 09:37:43 UTC

(In reply to comment #4)
> Didn't assign a CVE name for this one as the default perms for this is
> S_IWUSR|S_IRUSR. But MITRE might assign one.

Common Vulnerabilities and Exposures assigned an identifier CVE-2011-2534 to
the following vulnerability:

Buffer overflow in the clusterip_proc_write function in
net/ipv4/netfilter/ipt_CLUSTERIP.c in the Linux kernel before 2.6.39
might allow local users to cause a denial of service or have
unspecified other impact via a crafted write operation, related to
string data that lacks a terminating '\0' character.

References:
[1] http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2011-2534
[2] http://marc.info/?l=netfilter-devel&m=130036157327564&w=2
[3] http://marc.info/?l=netfilter&m=129978077509888&w=2
[4] http://www.openwall.com/lists/oss-security/2011/03/18/15
[5] http://www.openwall.com/lists/oss-security/2011/03/21/4
[6] http://www.openwall.com/lists/oss-security/2011/03/21/1
[7] http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=961ed183a9fd080cf306c659b8736007e44065a5
[8] http://www.kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.39

Comment 6 Eugene Teo (Security Response) 2011-07-19 06:08:28 UTC

Statement:

This issue did not affect the version of Linux kernel as shipped with Red Hat Enterprise Linux 4 as it did not have support for ipt_CLUSTERIP. This has been addressed in Red Hat Enterprise Linux 5, 6, and Red Hat Enterprise MRG via http://rhn.redhat.com/errata/RHSA-2011-0833.html, http://rhn.redhat.com/errata/RHSA-2011-0498.html, and http://rhn.redhat.com/errata/RHSA-2011-0500.html.