Xen · Xen · CVE-2016-1570
**Name of the Vulnerable Software and Affected Versions**
Xen versions 3.4.0 through 3.4.1
Xen versions 4.1.x through 4.6.x
**Description**
The issue allows local PV guests to obtain sensitive information, cause a denial of service, gain privileges, or have unspecified other impact. This is achieved via a crafted page identifier (MFN) to specific sub-ops in the HYPERVISOR mmuext op hypercall, including (1) MMUEXT MARK SUPER or (2) MMUEXT UNMARK SUPER, or through unknown vectors related to page table updates.
**Recommendations**
For Xen versions 3.4.0 and 3.4.1, update to a version that includes the fix for this issue.
For Xen versions 4.1.x through 4.6.x, update to a version that includes the fix for this issue.
As a temporary workaround, consider restricting access to the HYPERVISOR mmuext op hypercall to minimize the risk of exploitation.