Xen Hypervisor Function Error Condition Handling Lock Release Failure Guest-to-Host DoS (XSA-235)

medium Nessus Plugin ID 102842

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 flaw in the xenmem_add_to_physmap_one() function in arch/arm/mm.c that is triggered as the application fails to release a lock when handling certain error conditions. This may allow a privileged attacker within a guest to block a physical CPU, resulting in a denial of service.

This issue only affects ARM systems. x86 systems are not affected.

Note that Nessus has checked the changeset versions based on the xen.git change log. Nessus did not check guest hardware configurations or if patches were applied manually to the source code before a recompile and reinstall.

Solution

Apply the appropriate patch according to the vendor advisory.

See Also

http://xenbits.xen.org/xsa/advisory-235.html

https://xenbits.xen.org/gitweb/?p=xen.git;a=summary

Plugin Details

Severity: Medium

ID: 102842

File Name: xen_server_XSA-235.nasl

Version: 1.6

Type: local

Family: Misc.

Published: 8/30/2017

Updated: 6/3/2021

Configuration: Enable paranoid mode

Supported Sensors: Nessus

Risk Information

CVSS v2

Risk Factor: Medium

Base Score: 4.3

Temporal Score: 3.2

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

CVSS v3

Risk Factor: Medium

Base Score: 5.9

Temporal Score: 5.2

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

Patch Publication Date: 8/23/2017

Vulnerability Publication Date: 8/23/2017

Reference Information

BID: 100496

IAVB: 2017-B-0115-S