Xen Insufficient Cache Write-Back (XSA-321)

high Nessus Plugin ID 138363

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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 and potential privilege escalation due to an insufficient cache write-back under VT-d. A malicious guest may be able to retain read/write DMA access to frames returned to Xen's free pool, and later reused to access sensitive information pertaining to other guests to crash the host, resulting in a denial of service and privilege escalation.

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 or workaround according to the vendor advisory.

Plugin Details

Severity: High

ID: 138363

File Name: xen_server_XSA-321.nasl

Version: 1.5

Type: local

Family: Misc.

Published: 7/10/2020

Updated: 10/28/2020

Configuration: Enable paranoid mode

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: High

Score: 7.3

CVSS v2

Risk Factor: Medium

Base Score: 6.1

Temporal Score: 4.5

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

CVSS Score Source: CVE-2020-15565

CVSS v3

Risk Factor: High

Base Score: 8.8

Temporal Score: 7.7

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

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:xen:xen

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

Exploit Ease: No known exploits are available

Patch Publication Date: 7/7/2020

Vulnerability Publication Date: 7/7/2020

Reference Information

CVE: CVE-2020-15565

IAVB: 2020-B-0034-S

Detections

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