Xen Hypervisor TLB Flush Request Handling Race Condition System Memory Access Guest-to-Host Privilege Escalation (XSA-241)

high Nessus Plugin ID 103976
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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 a race condition that is triggered when handling TLB flush requests. This allows an attacker on the guest to access all system memory, allowing them to cause a denial of service, disclose sensitive information, or gain elevated privileges on the host.

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-241.html

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

Plugin Details

Severity: High

ID: 103976

File Name: xen_server_XSA-241.nasl

Version: 1.7

Type: local

Family: Misc.

Published: 10/19/2017

Updated: 6/3/2021

Dependencies: xen_server_detect.nbin

Configuration: Enable paranoid mode

Risk Information

CVSS Score Source: CVE-2017-15595

VPR

Risk Factor: High

Score: 7.3

CVSS v2

Risk Factor: High

Base Score: 7.2

Temporal Score: 5.6

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

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

CVSS v3

Risk Factor: High

Base Score: 8.8

Temporal Score: 7.9

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

Temporal Vector: E:P/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:xen:xen

Required KB Items: installed_sw/Xen Hypervisor, Settings/ParanoidReport

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 10/12/2017

Vulnerability Publication Date: 10/12/2017

Reference Information

CVE: CVE-2017-15588, CVE-2017-15589, CVE-2017-15590, CVE-2017-15591, CVE-2017-15592, CVE-2017-15593, CVE-2017-15594, CVE-2017-15595, CVE-2017-15596

BID: 101490, 101496, 101500

IAVB: 2017-B-0142-S