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Xen Project Restartable PV Type Change Operations Elevation of Privilege Vulnerability (XSA-310)

medium Nessus Plugin ID 132316

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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 an elevation of privilege vulnerability due to race conditions in the pagetable promotion and demotion operations. An authenticated, remote attacker can exploit this issue, by triggering race conditions and cause Xen to drop or retain extra type counts, to get write access to in-use pagetables and potentially gain elevated privileges.

Advisory XSA-310 addresses edge-cases not identified in XSA-299. HVM and PVH guests cannot exercise this vulnerability. ARM systems are not vulnerable because ARM guests are all PVH.

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

https://xenbits.xen.org/xsa/advisory-310.html

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

Plugin Details

Severity: Medium

ID: 132316

File Name: xen_server_XSA-310.nasl

Version: 1.3

Type: local

Family: Misc.

Published: 12/19/2019

Updated: 7/10/2020

Configuration: Enable paranoid mode

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 5.9

CVSS v2

Risk Factor: Medium

Base Score: 6

Temporal Score: 4.4

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

CVSS Score Source: CVE-2019-19580

CVSS v3

Risk Factor: Medium

Base Score: 6.6

Temporal Score: 5.8

Vector: CVSS:3.0/AV:N/AC:H/PR:H/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: 12/11/2019

Vulnerability Publication Date: 12/11/2019

Reference Information

CVE: CVE-2019-19580

IAVB: 2019-B-0091-S