Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS : LibVNCServer vulnerabilities (USN-4407-1)

critical Nessus Plugin ID 138132

Synopsis

The remote Ubuntu host is missing one or more security updates.

Description

It was discovered that LibVNCServer incorrectly handled decompressing data. An attacker could possibly use this issue to cause LibVNCServer to crash, resulting in a denial of service. (CVE-2019-15680) It was discovered that an information disclosure vulnerability existed in LibVNCServer when sending a ServerCutText message. An attacker could possibly use this issue to expose sensitive information. This issue only affected Ubuntu 19.10, Ubuntu 18.04 LTS, and Ubuntu 16.04 LTS.
(CVE-2019-15681) It was discovered that LibVNCServer incorrectly handled cursor shape updates. If a user were tricked in to connecting to a malicious server, an attacker could possibly use this issue to cause LibVNCServer to crash, resulting in a denial of service, or possibly execute arbitrary code. This issue only affected Ubuntu 19.10, Ubuntu 18.04 LTS, and Ubuntu 16.04 LTS. (CVE-2019-15690, CVE-2019-20788) It was discovered that LibVNCServer incorrectly handled decoding WebSocket frames. An attacker could possibly use this issue to cause LibVNCServer to crash, resulting in a denial of service, or possibly execute arbitrary code. This issue only affected Ubuntu 19.10, Ubuntu 18.04 LTS, and Ubuntu 16.04 LTS. (CVE-2017-18922).

Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

Solution

Update the affected packages.

See Also

https://ubuntu.com/security/notices/USN-4407-1

Plugin Details

Severity: Critical

ID: 138132

File Name: ubuntu_USN-4407-1.nasl

Version: 1.8

Type: local

Agent: unix

Published: 7/6/2020

Updated: 10/20/2023

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

Risk Information

VPR

Risk Factor: High

Score: 7.4

CVSS v2

Risk Factor: High

Base Score: 7.5

Temporal Score: 5.9

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

CVSS Score Source: CVE-2019-20788

CVSS v3

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: CVSS:3.0/E:P/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:canonical:ubuntu_linux:libvncclient1, p-cpe:/a:canonical:ubuntu_linux:libvncserver-config, p-cpe:/a:canonical:ubuntu_linux:libvncserver-dev, p-cpe:/a:canonical:ubuntu_linux:libvncserver1, cpe:/o:canonical:ubuntu_linux:16.04:-:lts, cpe:/o:canonical:ubuntu_linux:18.04:-:lts, cpe:/o:canonical:ubuntu_linux:20.04:-:lts

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

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 7/1/2020

Vulnerability Publication Date: 10/29/2019

Reference Information

CVE: CVE-2017-18922, CVE-2019-15680, CVE-2019-15681, CVE-2019-15690, CVE-2019-20788

IAVA: 2020-A-0381

USN: 4407-1