The v9fs_xattrcreate function in hw/9pfs/9p.c in QEMU (aka Quick Emulator) allows local guest OS administrators to obtain sensitive host heap memory information by reading xattribute values before writing to them.
git.qemu.org/?p=qemu.git%3Ba=commit%3Bh=eb687602853b4ae656e9236ee4222609f3a6887d
www.openwall.com/lists/oss-security/2016/10/28/1
www.openwall.com/lists/oss-security/2016/10/30/7
www.securityfocus.com/bid/93955
lists.debian.org/debian-lts-announce/2018/11/msg00038.html
lists.gnu.org/archive/html/qemu-devel/2016-10/msg01790.html
security.gentoo.org/glsa/201611-11