GLSA 201701-30: vzctl: Security bypass

http://security.gentoo.org/

Severity:	normal
Title:	vzctl: Security bypass
Date:	01/11/2017
Bugs:	#560522
ID:	201701-30

Synopsis

A vulnerability in vzctl might allow attackers to gain control over ploop containers.

Background

vzctl is a set of control tools for the OpenVZ server virtualization solution.

Affected packages

Package	Vulnerable	Unaffected	Architecture(s)
sys-cluster/vzctl	< 4.9.4	>= 4.9.4	All supported architectures

Description

It was discovered that vzctl determined the virtual environment (VE) layout based on the presence of root.hdd/DiskDescriptor.xml in the VE private directory. This allows local simfs container (CT) root users to change the root password for arbitrary ploop containers. This is demonstrated by a symlink attack on the ploop container root.hdd file which can then be used to access a control panel.

Impact

An attacker with root privileges, in a simfs-based container, could gain control over ploop-based containers.

Workaround

There is no known workaround at this time.

Resolution

All vzctl users should upgrade to the latest version:

      # emerge --sync
      # emerge --ask --oneshot --verbose ">=sys-cluster/vzctl-4.9.4"

References

CVE-2015-6927

Availability

This GLSA and any updates to it are available for viewing at the Gentoo Security Website: http://security.gentoo.org/glsa/glsa-201701-30.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.