CVE-2015-1779

El decodificador de frames websocket VNC en QEMU permite a atacantes remotos causar una denegación de servicio (consumo de CPU y memoria) a través de una gran (1) carga útil websocket o (2) sección de cabeceras HTTP

It was found that the QEMU's websocket frame decoder processed incoming frames without limiting resources used to process the header and the payload. An attacker able to access a guest's VNC console could use this flaw to trigger a denial of service on the host by exhausting all available memory and CPU.

Jason Geffner discovered that QEMU incorrectly handled the virtual floppy driver. This issue is known as VENOM. A malicious guest could use this issue to cause a denial of service, or possibly execute arbitrary code on the host as the user running the QEMU process. In the default installation, when QEMU is used with libvirt, attackers would be isolated by the libvirt AppArmor profile. Daniel P. Berrange discovered that QEMU incorrectly handled VNC websockets. A remote attacker could use this issue to cause QEMU to consume memory, resulting in a denial of service. This issue only affected Ubuntu 14.04 LTS, Ubuntu 14.10 and Ubuntu 15.04. Various other issues were also addressed.