FreeBSD : xen-kernel -- x86: Missing SMAP whitelisting in 32-bit exception / event delivery (04cf89e3-5854-11e6-b334-002590263bf5)

Medium Nessus Plugin ID 92675

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VPR Score: 3.6

Synopsis

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

Description

The Xen Project reports :

Supervisor Mode Access Prevention is a hardware feature designed to make an Operating System more robust, by raising a pagefault rather than accidentally following a pointer into userspace. However, legitimate accesses into userspace require whitelisting, and the exception delivery mechanism for 32bit PV guests wasn't whitelisted.

A malicious 32-bit PV guest kernel can trigger a safety check, crashing the hypervisor and causing a denial of service to other VMs on the host.

Solution

Update the affected package.

See Also

https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=211482

http://xenbits.xen.org/xsa/advisory-183.html

http://www.nessus.org/u?d67acf87

Plugin Details

Severity: Medium

ID: 92675

File Name: freebsd_pkg_04cf89e3585411e6b334002590263bf5.nasl

Version: 2.9

Type: local

Published: 2016/08/02

Updated: 2021/01/04

Dependencies: 12634

Risk Information

Risk Factor: Medium

VPR Score: 3.6

CVSS v2.0

Base Score: 4.9

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

CVSS v3.0

Base Score: 6.2

Vector: CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/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: 2016/08/02

Vulnerability Publication Date: 2016/07/26

Reference Information

CVE: CVE-2016-6259

IAVB: 2016-B-0118-S