Arbitrary File Read

openstack-nova is vulnerable to arbitrary file read. A flaw was discovered in the OpenStack Compute (nova) snapshot feature when using the libvirt driver. A compute user could overwrite an attached instance disk with a malicious header specifying a backing file, and then request a snapshot, causing a file from the compute host to be leaked. This flaw only affects LVM or Ceph setups, or setups using filesystem storage with use_cow_images = False.