The remote Debian host is missing a security-related update.
Several vulnerabilities were discovered in qemu, a fast processor emulator. - CVE-2014-3689 The Advanced Threat Research team at Intel Security reported that guest provided parameter were insufficiently validated in rectangle functions in the vmware-vga driver. A privileged guest user could use this flaw to write into qemu address space on the host, potentially escalating their privileges to those of the qemu host process. - CVE-2014-7815 James Spadaro of Cisco reported insufficiently sanitized bits_per_pixel from the client in the QEMU VNC display driver. An attacker having access to the guest's VNC console could use this flaw to crash the guest.
Upgrade the qemu packages. For the stable distribution (wheezy), these problems have been fixed in version 1.1.2+dfsg-6+deb7u5.