CVE-2016-5008

libvirt en versiones anteriores a 2.0.0 desactiva inadecuadamente la comprobación de contraseñas cuando la contraseña en un servidor VNC está establecida en una cadena vacía, lo que permite a atacantes remotos eludir la autenticación y establecer una sesióin VNC conectándose al servidor.

It was found that setting a VNC password to an empty string in libvirt did not disable all access to the VNC server as documented, instead it allowed access with no authentication required. An attacker could use this flaw to access a VNC server with an empty VNC password without any authentication.

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. 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. Various other issues were also addressed.