The megasas_dcmd_cfg_read function in hw/scsi/megasas.c in QEMU, when built with MegaRAID SAS 8708EM2 Host Bus Adapter emulation support, uses an uninitialized variable, which allows local guest administrators to read host memory via vectors involving a MegaRAID Firmware Interface (MFI) command.
https://lists.gnu.org/archive/html/qemu-devel/2016-05/msg04419.html
https://lists.debian.org/debian-lts-announce/2018/11/msg00038.html
https://bugzilla.redhat.com/show_bug.cgi?id=1339583
http://www.ubuntu.com/usn/USN-3047-2
http://www.ubuntu.com/usn/USN-3047-1