The change_process_uid function in os-posix.c in Qemu 0.14.0 and earlier does not properly drop group privileges when the -runas option is used, which allows local guest users to access restricted files on the host.
lists.fedoraproject.org/pipermail/package-announce/2012-June/081972.html
lists.opensuse.org/opensuse-updates/2012-02/msg00009.html
rhn.redhat.com/errata/RHSA-2011-1531.html
secunia.com/advisories/45187
secunia.com/advisories/45188
secunia.com/advisories/45419
secunia.com/advisories/47157
secunia.com/advisories/47992
ubuntu.com/usn/usn-1177-1
www.openwall.com/lists/oss-security/2011/07/12/15
www.openwall.com/lists/oss-security/2011/07/12/5
www.osvdb.org/74752
www.securityfocus.com/bid/48659
bugs.launchpad.net/qemu/+bug/807893
exchange.xforce.ibmcloud.com/vulnerabilities/68539
www.debian.org/security/2011/dsa-2282