FreeBSD : xen-kernel -- Uncontrolled creation of large page mappings by PV guests (3d9f6260-881d-11e5-ab94-002590263bf5)
High Nessus Plugin ID 86836
SynopsisThe remote FreeBSD host is missing a security-related update.
DescriptionThe Xen Project reports :
The code to validate level 2 page table entries is bypassed when certain conditions are satisfied. This means that a PV guest can create writable mappings using super page mappings. Such writable mappings can violate Xen intended invariants for pages which Xen is supposed to keep read-only. This is possible even if the 'allowsuperpage' command line option is not used.
Malicious PV guest administrators can escalate privilege so as to control the whole system.
SolutionUpdate the affected package.