The qemuDomainGetBlockIoTune function in qemu/qemu_driver.c in libvirt before 1.2.9, when a disk has been hot-plugged or removed from the live image, allows remote attackers to cause a denial of service (crash) or read sensitive heap information via a crafted blkiotune query, which triggers an out-of-bounds read.
Improper Restriction of Operations within the Bounds of a Memory Buffer The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary.