Detections
Analytics

Xen: missing IOMMU TLB flushing (XSA-442)

high Nessus Plugin ID 182972

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Synopsis

The remote Xen hypervisor installation is missing a security update.

Description

The caching invalidation guidelines from the AMD-Vi specification (48882—Rev 3.07-PUB—Oct 2022) is incorrect on some hardware, as devices will malfunction (see stale DMA mappings) if some fields of the DTE are updated but the IOMMU TLB is not flushed.

Such stale DMA mappings can point to memory ranges not owned by the guest, thus allowing access to unindented memory regions, leading to privilege escalation, denial of service (DoS) affecting the entire host, and information leaks.

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-442.html

Plugin Details

Severity: High

ID: 182972

File Name: xen_server_XSA-442.nasl

Version: 1.4

Type: local

Family: Misc.

Published: 10/12/2023

Updated: 1/15/2024

Configuration: Enable paranoid mode

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 5.9

CVSS v2

Risk Factor: Medium

Base Score: 6.8

Temporal Score: 5

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

CVSS Score Source: CVE-2023-34326

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 6.8

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/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: 10/10/2023

Vulnerability Publication Date: 10/10/2023

Reference Information

CVE: CVE-2023-34326

IAVB: 2023-B-0081-S