Xen Hypervisor I/O Intercept Code Hypervisor Stack Guest-to-Host Information Disclosure (XSA-239)

high Nessus Plugin ID 103974
New! Plugin Severity Now Using CVSS v3

The calculated severity for Plugins has been updated to use CVSS v3 by default. Plugins that do not have a CVSS v3 score will fall back to CVSS v2 for calculating severity. Severity display preferences can be toggled in the settings dropdown.

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 unspecified flaw in the hvmemul_do_io() function in arch/x86/hvm/emulate.c that is triggered as an internal structure may contain data from an uninitialized hypervisor stack slot. This may allow an attacker on the guest to gain access to potentially sensitive information from 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-239.html

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

Plugin Details

Severity: High

ID: 103974

File Name: xen_server_XSA-239.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