Integer overflow in the load_multiboot function in hw/i386/multiboot.c in QEMU (aka Quick Emulator) allows local guest OS users to execute arbitrary code on the host via crafted multiboot header address values, which trigger an out-of-bounds write.
www.debian.org/security/2017/dsa-3991
www.openwall.com/lists/oss-security/2017/09/07/2
www.securityfocus.com/bid/100694
access.redhat.com/errata/RHSA-2017:3368
access.redhat.com/errata/RHSA-2017:3369
access.redhat.com/errata/RHSA-2017:3466
access.redhat.com/errata/RHSA-2017:3470
access.redhat.com/errata/RHSA-2017:3471
access.redhat.com/errata/RHSA-2017:3472
access.redhat.com/errata/RHSA-2017:3473
access.redhat.com/errata/RHSA-2017:3474
lists.debian.org/debian-lts-announce/2018/09/msg00007.html
lists.nongnu.org/archive/html/qemu-devel/2017-09/msg01032.html
usn.ubuntu.com/3575-1/