CVE-2013-4554: Undefined Security Weakness

Xen 3.0.3 through 4.1.x possibly 4.1.6.1, 4.2.x possibly 4.2.3, and 4.3.x possibly 4.3.1 does not properly prevent access to hypercalls, which allows local guest users to gain privileges via a crafted application running in ring 1 or 2...