Red Hat Security Advisory 2012-1130-01 - The xen packages contain administration tools and the xend service for managing the kernel-xen kernel for virtualization on Red Hat Enterprise Linux. A flaw was found in the way the pyGrub boot loader handled compressed kernel images. A privileged guest user in a para-virtualized guest could use this flaw to create a crafted kernel image that, when attempting to boot it, could result in an out-of-memory condition in the privileged domain.
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