USN-3576-1: libvirt vulnerabilities

20 February 2018

Several security issues were fixed in libvirt.

Releases

Packages

  • libvirt - Libvirt virtualization toolkit

Details

Vivian Zhang and Christoph Anton Mitterer discovered that libvirt
incorrectly disabled password authentication when the VNC password was set
to an empty string. A remote attacker could possibly use this issue to
bypass authentication, contrary to expectations. This issue only affected
Ubuntu 14.04 LTS and Ubuntu 16.04 LTS. (CVE-2016-5008)

Daniel P. Berrange discovered that libvirt incorrectly handled validating
SSL/TLS certificates. A remote attacker could possibly use this issue to
obtain sensitive information. This issue only affected Ubuntu 17.10.
(CVE-2017-1000256)

Daniel P. Berrange and Peter Krempa discovered that libvirt incorrectly
handled large QEMU replies. An attacker could possibly use this issue to
cause libvirt to crash, resulting in a denial of service. (CVE-2018-5748)

Pedro Sampaio discovered that libvirt incorrectly handled the libnss_dns.so
module. An attacker in a libvirt_lxc session could possibly use this issue
to execute arbitrary code. This issue only affected Ubuntu 16.04 LTS and
Ubuntu 17.10. (CVE-2018-6764)

Update instructions

The problem can be corrected by updating your system to the following package versions:

Ubuntu 17.10
Ubuntu 16.04
Ubuntu 14.04

After a standard system update you need to reboot your computer to make
all the necessary changes.