Xen Hypervisor I/O Intercept Code Hypervisor Stack Guest-to-Host Information Disclosure (XSA-239)
Medium Nessus Plugin ID 103974
Synopsis
The remote Xen hypervisor installation is missing a security update.
Description
According to its self-reported version number, the Xen hypervisor installed on the remote host is affected by an unspecified flaw in the hvmemul_do_io() function in arch/x86/hvm/emulate.c that is triggered as an internal structure may contain data from an uninitialized hypervisor stack slot. This may allow an attacker on the guest to gain access to potentially sensitive information from the host.
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.
Solution
Apply the appropriate patch according to the vendor advisory.