Xen Denial of Service vulnerability (XSA-304)

medium Nessus Plugin ID 134172
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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 a denial of service vulnerability. An erratum exists across some CPUs whereby an instruction fetch may cause a machine check error if the pagetables have been updated in a specific manner without invalidating the TLB. The x86 architecture explicitly permits modification of the pagetables without TLB invalidation, but in this corner case, the impacted core ceases operating and an unexpected machine check or system reset occurs. This corner case can be triggered by guest kernels.

Solution

Apply the appropriate patch according to the vendor advisory.

See Also

http://www.nessus.org/u?1d5ba048

Plugin Details

Severity: Medium

ID: 134172

File Name: xen_server_XSA-304.nasl

Version: 1.2

Type: local

Family: Misc.

Published: 3/2/2020

Updated: 3/3/2020

Dependencies: xen_server_detect.nbin

Configuration: Enable paranoid mode

Risk Information

CVSS Score Source: CVE-2018-12207

VPR

Risk Factor: Medium

Score: 6

CVSS v2

Risk Factor: Medium

Base Score: 4.9

Temporal Score: 3.6

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

Temporal Vector: E:U/RL:OF/RC:C

CVSS v3

Risk Factor: Medium

Base Score: 6.5

Temporal Score: 5.7

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

Temporal Vector: E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:xen:xen

Required KB Items: installed_sw/Xen Hypervisor, Settings/ParanoidReport

Exploit Ease: No known exploits are available

Patch Publication Date: 11/12/2019

Vulnerability Publication Date: 11/12/2019

Reference Information

CVE: CVE-2018-12207