Xen mishandle IOMMU TLB flushes DoS (XSA-346)

high Nessus Plugin ID 144976


The remote Xen hypervisor installation is missing a security update.


A denial of service (DoS) vulnerability exists in Xen x86 HVM and PVH guest OS users due to mishandled coalesce per-page IOMMU TLB flushes. A guest OS user might be able to cause denial of service (data corruption), data leak, or possibly gain privileges.

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


Apply the appropriate patch or workaround according to the vendor advisory.

See Also


Plugin Details

Severity: High

ID: 144976

File Name: xen_server_XSA-346.nasl

Version: 1.3

Type: local

Family: Misc.

Published: 1/14/2021

Updated: 6/3/2021

Configuration: Enable paranoid mode

Risk Information

CVSS Score Source: CVE-2020-27671


Risk Factor: High

Score: 7.3


Risk Factor: Medium

Base Score: 6.9

Temporal Score: 5.1

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

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


Risk Factor: High

Base Score: 7.8

Temporal Score: 6.8

Vector: CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/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: 10/20/2020

Vulnerability Publication Date: 10/20/2020

Reference Information

CVE: CVE-2020-27671

IAVB: 2020-B-0056-S

CWE: 269