USN-3576-1: libvirt vulnerabilities

20 February 2018

libvirt vulnerabilities

A security issue affects these releases of Ubuntu and its derivatives:

  • Ubuntu 17.10
  • Ubuntu 16.04 LTS
  • Ubuntu 14.04 LTS

Summary

Several security issues were fixed in libvirt.

Software Description

  • 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
libvirt-bin - 3.6.0-1ubuntu6.3
libvirt0 - 3.6.0-1ubuntu6.3
Ubuntu 16.04 LTS
libvirt-bin - 1.3.1-1ubuntu10.19
libvirt0 - 1.3.1-1ubuntu10.19
Ubuntu 14.04 LTS
libvirt-bin - 1.2.2-0ubuntu13.1.26
libvirt0 - 1.2.2-0ubuntu13.1.26

To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.

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

References