Xen Speculative Side Channel Information Disclosure (XSA-320)

medium Nessus Plugin ID 149085
New! Plugin Severity Now Using CVSS v3

The calculated severity for Plugins has been updated to use CVSS v3 by default. Plugins that do not have a CVSS v3 score will fall back to CVSS v2 for calculating severity. Severity display preferences can be toggled in the settings dropdown.

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 an issue.
Incomplete cleanup from specific special register read operations in some Intel(R) Processors may allow an authenticated user to potentially enable information disclosure via local access. An attacker, which could include a malicious untrusted user process on a trusted guest, or an untrusted guest, can sample the contents of certain off-core accesses by other cores in the system. Only x86 processors are vulnerable. ARM processors are not believed to be vulnerable.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Apply the appropriate patch according to the vendor advisory.

See Also

https://xenbits.xen.org/xsa/advisory-320.html

Plugin Details

Severity: Medium

ID: 149085

File Name: xen_server_XSA-320.nasl

Version: 1.2

Type: local

Family: Misc.

Published: 4/29/2021

Updated: 4/30/2021

Dependencies: xen_server_detect.nbin

Configuration: Enable paranoid mode

Risk Information

CVSS Score Source: CVE-2020-0543

VPR

Risk Factor: Medium

Score: 6.1

CVSS v2

Risk Factor: Low

Base Score: 2.1

Temporal Score: 1.6

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

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

CVSS v3

Risk Factor: Medium

Base Score: 5.5

Temporal Score: 4.8

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

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: 6/9/2020

Vulnerability Publication Date: 6/9/2020

Reference Information

CVE: CVE-2020-0543