FreeBSD : xen-kernel -- x86 task switch to VM86 mode mis-handled (523bb0b7-ba4d-11e6-ae1b-002590263bf5)

high Nessus Plugin ID 95506

Language:

Synopsis

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

Description

The Xen Project reports :

LDTR, just like TR, is purely a protected mode facility. Hence even when switching to a VM86 mode task, LDTR loading needs to follow protected mode semantics. This was violated by the code.

On SVM (AMD hardware): a malicious unprivileged guest process can escalate its privilege to that of the guest operating system.

On both SVM and VMX (Intel hardware): a malicious unprivileged guest process can crash the guest.

Solution

Update the affected package.

See Also

https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=214936

https://xenbits.xen.org/xsa/advisory-192.html

http://www.nessus.org/u?5d98f61d

Plugin Details

Severity: High

ID: 95506

File Name: freebsd_pkg_523bb0b7ba4d11e6ae1b002590263bf5.nasl

Version: 3.5

Type: local

Published: 12/5/2016

Updated: 1/4/2021

Risk Information

VPR

Risk Factor: Medium

Score: 5.9

CVSS v2

Risk Factor: Medium

Base Score: 4.6

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

CVSS v3

Risk Factor: High

Base Score: 7.8

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

Vulnerability Information

CPE: p-cpe:/a:freebsd:freebsd:xen-kernel, 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-2016-9382