FreeBSD : xen-kernel -- x86 64-bit bit test instruction emulation broken (56f0f11e-ba4d-11e6-ae1b-002590263bf5)

High Nessus Plugin ID 95509

Synopsis

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

Description

The Xen Project reports :

The x86 instructions BT, BTC, BTR, and BTS, when used with a destination memory operand and a source register rather than an immediate operand, access a memory location offset from that specified by the memory operand as specified by the high bits of the register source.

A malicious guest can modify arbitrary memory, allowing for arbitrary code execution (and therefore privilege escalation affecting the whole host), a crash of the host (leading to a DoS), or information leaks.
The vulnerability is sometimes exploitable by unprivileged guest user processes.

Solution

Update the affected package.

See Also

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

https://xenbits.xen.org/xsa/advisory-195.html

http://www.nessus.org/u?20be6a77

Plugin Details

Severity: High

ID: 95509

File Name: freebsd_pkg_56f0f11eba4d11e6ae1b002590263bf5.nasl

Version: 3.4

Type: local

Published: 2016/12/05

Updated: 2018/11/10

Dependencies: 12634

Risk Information

Risk Factor: High

CVSS v2.0

Base Score: 7.2

Vector: CVSS2#AV:L/AC:L/Au:N/C:C/I:C/A:C

CVSS v3.0

Base Score: 8.8

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/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: 2016/12/04

Vulnerability Publication Date: 2016/11/22

Reference Information

CVE: CVE-2016-9383