The HDA audio device model did not check for zero-length Buffer Descriptor List (BDL) entries when starting a stream. A zero-length entry caused an out-of-bounds read or write during DMA transfer processing. BDL fields were also subject to modification by the guest after validation.
A malicious guest can crash the bhyve process or potentially execute arbitrary code in the host userspace context running the virtual machine, subject to bhyves Capsicum sandbox.
Weakness
The product reads from a buffer using buffer access mechanisms such as indexes or pointers that reference memory locations after the targeted buffer.