Citrix XenServer Multiple Vulnerabilities (CTX216071)

medium Nessus Plugin ID 93608

Synopsis

The remote host is affected by multiple vulnerabilities.

Description

The version of Citrix XenServer running on the remote host is missing a security hotfix. It is, therefore, affected by multiple vulnerabilities :

- A flaw exists due to improper handling of pagetable walks that contain recursive L3 pagetable entries. An attacker on the guest can exploit this to gain elevated privileges. (CVE-2016-7092)

- A flaw exists due to improper handling of instruction pointer truncation when emulating HVM instructions. An attacker on the guest can exploit this to gain elevated privileges. (CVE-2016-7093)

- An overflow condition exists in the x86 HVM guests due to improper handling of writing to pagetables, specifically when the guest is running shadow paging using a subset of the x86 emulator. An attacker on the guest can exploit this to cause a denial of service condition on the host. (CVE-2016-7094)

- A use-after-free error exists when calling the EVTCHNOP_init_control operation with a bad guest frame number. An attacker on the guest can exploit this, by freeing a control structure without also clearing the corresponding pointer, to crash the host or potentially gain elevated privileges. (CVE-2016-7154)

Solution

Apply the appropriate hotfix according to the vendor advisory.

See Also

https://support.citrix.com/article/CTX216071

Plugin Details

Severity: Medium

ID: 93608

File Name: citrix_xenserver_CTX216071.nasl

Version: 1.12

Type: local

Family: Misc.

Published: 9/20/2016

Updated: 11/14/2019

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.5

CVSS v2

Risk Factor: High

Base Score: 7.2

Temporal Score: 5.3

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

CVSS Score Source: CVE-2016-7154

CVSS v3

Risk Factor: Medium

Base Score: 6.7

Temporal Score: 5.8

Vector: CVSS:3.0/AV:L/AC:L/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:/a:citrix:xenserver

Required KB Items: Host/local_checks_enabled, Host/XenServer/version

Exploit Ease: No known exploits are available

Patch Publication Date: 9/8/2016

Vulnerability Publication Date: 9/8/2016

Reference Information

CVE: CVE-2016-7092, CVE-2016-7093, CVE-2016-7094, CVE-2016-7154

BID: 92862, 92863, 92864, 92865