FreeBSD : xen-tools -- qemu incautious about shared ring processing (58685e23-ba4d-11e6-ae1b-002590263bf5)

high Nessus Plugin ID 95510



The remote FreeBSD host is missing a security-related update.


The Xen Project reports :

The compiler can emit optimizations in qemu which can lead to double fetch vulnerabilities. Specifically data on the rings shared between qemu and the hypervisor (which the guest under control can obtain mappings of) can be fetched twice (during which time the guest can alter the contents) possibly leading to arbitrary code execution in qemu.

Malicious administrators can exploit this vulnerability to take over the qemu process, elevating its privilege to that of the qemu process.

In a system not using a device model stub domain (or other techniques for deprivileging qemu), malicious guest administrators can thus elevate their privilege to that of the host.


Update the affected package.

See Also

Plugin Details

Severity: High

ID: 95510

File Name: freebsd_pkg_58685e23ba4d11e6ae1b002590263bf5.nasl

Version: 3.5

Type: local

Published: 12/5/2016

Updated: 1/4/2021

Risk Information


Risk Factor: Medium

Score: 6.5


Risk Factor: Medium

Base Score: 6.9

Vector: AV:L/AC:M/Au:N/C:C/I:C/A:C


Risk Factor: High

Base Score: 7.5

Vector: CVSS:3.0/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H

Vulnerability Information

CPE: p-cpe:/a:freebsd:freebsd:xen-tools, cpe:/o:freebsd:freebsd

Required KB Items: Host/local_checks_enabled, Host/FreeBSD/release, Host/FreeBSD/pkg_info

Patch Publication Date: 12/4/2016

Vulnerability Publication Date: 11/22/2016

Reference Information

CVE: CVE-2016-9381