Xen Multiple Vulnerabilities (XSA-186, XSA-187)
High Nessus Plugin ID 93802
SynopsisThe remote Xen hypervisor installation is missing a security update.
DescriptionAccording to its self-reported version number, the Xen hypervisor installed on the remote host is affected by multiple vulnerabilities :
- A flaw exists due to improper handling of instruction pointer truncation when emulating HVM instructions. An attacker on the guest can exploit this to gain elevated privileges on the host. (CVE-2016-7093)
- An overflow condition exists due to x86 HVM guests running with shadow paging using a subset of the x86 emulator to handle the guest writing to pagetables. An attacker on the guest can exploit this to cause a denial of service condition on the host. (CVE-2016-7094)
Note that Nessus has checked the changeset versions based on the xen.git change log. Nessus did not check guest hardware configurations or if patches were applied manually to the source code before a recompile and reinstall.
SolutionApply the appropriate patch according to the vendor advisory.