Bug 915718 (CVE-2013-1766)

Summary: CVE-2013-1766 libvirt: kvm-group writable storage
Product: [Other] Security Response Reporter: Petr Matousek <pmatouse>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED NOTABUG QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: acathrow, berrange, bsarathy, clalancette, dyasny, itamar, jforbes, jlieskov, jyang, laine, libvirt-maint, veillard, virt-maint
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: 2013-02-26 11:26:53 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:    
Bug Blocks: 915719    

Description Petr Matousek 2013-02-26 11:25:12 UTC 
libvirtd in privileged (root) mode runs qemu/kvm guests with a different
user. It set owner/group of storage used by this guests to this user and
group. In Debian this is libvirt-qemu:kvm.

| brw-rw---T 1 libvirt-qemu kvm  254, 11 Feb 25 17:08 /dev/dm-11
| brw-rw---T 1 libvirt-qemu kvm  254, 12 Feb 25 17:50 /dev/dm-12

The kvm group is used for generic access control on /dev/kvm, so a lot
of users may have access to this group.

| crw-rw---T 1 root kvm 10, 232 Feb 25 18:04 kvm

This allows write access to unrelated users to this storage.

Affected is at least Debian Squeeze (0.8.3-5+squeeze2) and Debian
experimental (1.0.1-2).

References:
http://bugs.debian.org/701649
http://seclists.org/oss-sec/2013/q1/440
http://seclists.org/oss-sec/2013/q1/447
Comment 1 Petr Matousek 2013-02-26 11:26:29 UTC 
Statement:

Not vulnerable.

This issue did not affect the versions of the libvirt package as shipped with Red Hat Enterprise Linux 5 and 6.
Comment 2 Jan Lieskovsky 2013-03-20 15:37:14 UTC 
Other references:
  http://www.debian.org/security/2013/dsa-2650
  http://www.securityfocus.com/bid/58178
  http://secunia.com/advisories/52628