XENMEM_aquire_resources Error Path DoS (XSA-334)

medium Nessus Plugin ID 144794
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Synopsis

The remote Xen hypervisor installation is missing a security update.

Description

A denial of service (DoS) vulnerability exists in Xen servers XENMEM_acquire_resource due to an error path exiting without releasing an RCU (Read, Copy, Update) reference. An authenticated, local attacker can exploit this issue, via a malicious HVM stubdomain which can cause an RCU reference to be leaked, that leads to subsequent administration operations, (e.g. CPU offline) to livelock, resulting in a host DoS.

Solution

Apply the appropriate patch or mitigation as described in the vendor advisory.

See Also

https://xenbits.xen.org/xsa/advisory-334.html

Plugin Details

Severity: Medium

ID: 144794

File Name: xen_server_XSA-334.nasl

Version: 1.3

Type: local

Family: Misc.

Published: 1/7/2021

Updated: 6/3/2021

Dependencies: xen_server_detect.nbin

Configuration: Enable paranoid mode

Risk Information

CVSS Score Source: CVE-2020-25598

VPR

Risk Factor: Medium

Score: 4.4

CVSS v2

Risk Factor: Low

Base Score: 2.1

Temporal Score: 1.6

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

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:N/I:N/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: 9/22/2020

Vulnerability Publication Date: 9/22/2020

Reference Information

CVE: CVE-2020-25598

IAVB: 2020-B-0056-S

CWE: 670