QEMU is vulnerable to denial of service. A heap-based buffer overflow flaw was discovered in the way QEMUβs AMD PC-Net II Ethernet Controller emulation received certain packets in loopback mode. A privileged user (with the CAP_SYS_RAWIO capability) inside a guest could use this flaw to crash the host QEMU process (resulting in denial of service) or, potentially, execute arbitrary code with privileges of the host QEMU process.
rhn.redhat.com/errata/RHSA-2015-2694.html
rhn.redhat.com/errata/RHSA-2015-2695.html
rhn.redhat.com/errata/RHSA-2015-2696.html
www.debian.org/security/2016/dsa-3469
www.debian.org/security/2016/dsa-3470
www.debian.org/security/2016/dsa-3471
www.openwall.com/lists/oss-security/2015/11/30/2
www.securityfocus.com/bid/78227
www.securitytracker.com/id/1034268
xenbits.xen.org/xsa/advisory-162.html
access.redhat.com/errata/RHSA-2015:2694
access.redhat.com/errata/RHSA-2015:2695
access.redhat.com/errata/RHSA-2015:2696
access.redhat.com/security/cve/CVE-2015-7504
access.redhat.com/security/updates/classification/#important
bugzilla.redhat.com/show_bug.cgi?id=1261461
lists.gnu.org/archive/html/qemu-devel/2015-11/msg06342.html
rhn.redhat.com/errata/RHSA-2015-2696.html
security.gentoo.org/glsa/201602-01
security.gentoo.org/glsa/201604-03