Describe CVE-2013-4154.
What is CVE-2013-4154?
The qemuAgentCommand function in libvirt before 1.1.1, when a guest agent is not configured, allows remote attackers to cause a denial of service (NULL pointer dereference and crash) via vectors related to "agent based cpu (un)plug," as demonstrated by the "virsh vcpucount foobar --guest" command..