Ubuntu 16.04 LTS : SSVNC vulnerabilities (USN-4547-2)

High Nessus Plugin ID 140929

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VPR Score: 5.9

Synopsis

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

Description

The remote Ubuntu 16.04 LTS host has a package installed that is affected by multiple vulnerabilities as referenced in the USN-4547-2 advisory.

- LibVNC before commit 7b1ef0ffc4815cab9a96c7278394152bdc89dc4d contains heap out-of-bound write vulnerability inside structure in VNC client code that can result remote code execution (CVE-2018-20020)

- LibVNC before commit c3115350eb8bb635d0fdb4dbbb0d0541f38ed19c contains a CWE-835: Infinite loop vulnerability in VNC client code. Vulnerability allows attacker to consume excessive amount of resources like CPU and RAM (CVE-2018-20021)

- LibVNC before 2f5b2ad1c6c99b1ac6482c95844a84d66bb52838 contains multiple weaknesses CWE-665: Improper Initialization vulnerability in VNC client code that allows attacker to read stack memory and can be abuse for information disclosure. Combined with another vulnerability, it can be used to leak stack memory layout and in bypassing ASLR (CVE-2018-20022)

- LibVNC before commit 4a21bbd097ef7c44bb000c3bd0907f96a10e4ce7 contains null pointer dereference in VNC client code that can result DoS. (CVE-2018-20024)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Update the affected ssvnc package.

See Also

https://ubuntu.com/security/notices/USN-4547-2

Plugin Details

Severity: High

ID: 140929

File Name: ubuntu_USN-4547-2.nasl

Version: 1.2

Type: local

Agent: unix

Published: 2020/09/29

Updated: 2020/11/24

Dependencies: 12634

Risk Information

Risk Factor: High

VPR Score: 5.9

CVSS Score Source: CVE-2018-20020

CVSS v2.0

Base Score: 7.5

Temporal Score: 5.5

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

Temporal Vector: CVSS2#E:U/RL:OF/RC:C

CVSS v3.0

Base Score: 9.8

Temporal Score: 8.5

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:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:canonical:ubuntu_linux:16.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:ssvnc

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

Exploit Ease: No known exploits are available

Patch Publication Date: 2020/09/28

Vulnerability Publication Date: 2018/12/19

Reference Information

CVE: CVE-2018-20020, CVE-2018-20021, CVE-2018-20022, CVE-2018-20024

USN: 4547-2