Ubuntu 16.04 LTS : libx11 vulnerability (USN-4966-2)

critical Nessus Plugin ID 149905


The remote Ubuntu host is missing a security update.


The remote Ubuntu 16.04 LTS host has packages installed that are affected by a vulnerability as referenced in the USN-4966-2 advisory. Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.


Update the affected packages.

See Also


Plugin Details

Severity: Critical

ID: 149905

File Name: ubuntu_USN-4966-2.nasl

Version: 1.5

Type: local

Agent: unix

Published: 5/25/2021

Updated: 1/17/2023

Supported Sensors: Agentless Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, Frictionless Assessment Azure, Nessus Agent

Risk Information


Risk Factor: Medium

Score: 6.7


Risk Factor: High

Base Score: 7.5

Temporal Score: 5.9

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

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

CVSS Score Source: CVE-2021-31535


Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.8

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

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

Vulnerability Information

CPE: cpe:/o:canonical:ubuntu_linux:16.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:libx11-6, p-cpe:/a:canonical:ubuntu_linux:libx11-6-udeb, p-cpe:/a:canonical:ubuntu_linux:libx11-data, p-cpe:/a:canonical:ubuntu_linux:libx11-dev, p-cpe:/a:canonical:ubuntu_linux:libx11-xcb-dev, p-cpe:/a:canonical:ubuntu_linux:libx11-xcb1

Required KB Items: Host/cpu, Host/Ubuntu, Host/Ubuntu/release, Host/Debian/dpkg-l

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 5/25/2021

Vulnerability Publication Date: 5/25/2021

Reference Information

CVE: CVE-2021-31535

USN: 4966-2