Memory leak in the audio/audio.c in QEMU (aka Quick Emulator) allows remote attackers to cause a denial of service (memory consumption) by repeatedly starting and stopping audio capture.
https://access.redhat.com/errata/RHSA-2017:2408
https://lists.debian.org/debian-lts-announce/2018/09/msg00007.html
https://lists.gnu.org/archive/html/qemu-devel/2017-04/msg05587.html