A very serious security problem has been found in the virtual floppy drive QEMU's code used by many computer virtualization platforms including Xen, KVM, VirtualBox, and the native QEMU client. It is called VENOM vulnerability. Because of this vulnerability, access to the hypervisor from a VPS could be granted.

VENOM, CVE-2015-3456, is a security vulnerability in the virtual floppy drive code used by many computer virtualization platforms. This vulnerability may allow an attacker to escape from the confines of an affected virtual machine (VM) guest and potentially obtain code-execution access to the host. Absent mitigation, this VM escape could open access to the host system and all other VMs running on that host, potentially giving adversaries significant elevated access to the hostís local network and adjacent systems.

Exploitation of the VENOM vulnerability can expose access to corporate intellectual property (IP), in addition to sensitive and personally identifiable information (PII), potentially impacting the thousands of organizations and millions of end users that rely on affected VMs for the allocation of shared computing resources, as well as connectivity, storage, security, and privacy.

To fix it you need update your system with yum/rpm, apt-get/aptitude.

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