GLSA 201612-10: libvirt: Directory traversal

http://security.gentoo.org/

Severity:	normal
Title:	libvirt: Directory traversal
Date:	12/04/2016
Bugs:	#568870
ID:	201612-10

Synopsis

Libvirt is vulnerable to directory traversal when using Access Control Lists (ACL).

Background

libvirt is a C toolkit for manipulating virtual machines.

Affected packages

Package	Vulnerable	Unaffected	Architecture(s)
app-emulation/libvirt	< 1.2.21-r1	>= 1.2.21-r1	All supported architectures

Description

Normally, only privileged users can coerce libvirt into creating or opening existing files using the virStorageVol APIs; and such users already have full privilege to create any domain XML.

But in the case of fine-grained ACLs, it is feasible that a user can be granted storage_vol:create but not domain:write, and it violates assumptions if such a user can abuse libvirt to access files outside of the storage pool.

Impact

When fine-grained Access Control Lists (ACL) are in effect, an authenticated local user with storage_vol:create permission but without domain:write permission maybe able to create or access arbitrary files outside of the storage pool.

Workaround

Don’t make use of fine-grained Access Control Lists (ACL) in libvirt; In Gentoo, libvirt’s ACL support is disable by default unless you enable the “policykit” USE flag.

Resolution

All libvirt users should upgrade to the latest version:

      # emerge --sync
      # emerge --ask --oneshot --verbose ">=app-emulation/libvirt-1.2.21-r1"

References

CVE-2015-5313

Availability

This GLSA and any updates to it are available for viewing at the Gentoo Security Website: http://security.gentoo.org/glsa/glsa-201612-10.xml

Concerns?

Security is a primary focus of Gentoo Linux and ensuring the confidentiality and security of our users machines is of utmost importance to us. Any security concerns should be addressed to security@gentoo.org or alternatively, you may file a bug at https://bugs.gentoo.org.