Amazon Linux AMI : tigervnc (ALAS-2020-1470) (deprecated)

high Nessus Plugin ID 144468
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

This plugin has been deprecated.

Description

The version of tested product installed on the remote host is prior to tested version. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS-2020-1470 advisory.

- TigerVNC version prior to 1.10.1 is vulnerable to stack use-after-return, which occurs due to incorrect usage of stack memory in ZRLEDecoder. If decoding routine would throw an exception, ZRLEDecoder may try to access stack variable, which has been already freed during the process of stack unwinding. Exploitation of this vulnerability could potentially result into remote code execution. This attack appear to be exploitable via network connectivity. (CVE-2019-15691)

- TigerVNC version prior to 1.10.1 is vulnerable to heap buffer overflow. Vulnerability could be triggered from CopyRectDecoder due to incorrect value checks. Exploitation of this vulnerability could potentially result into remote code execution. This attack appear to be exploitable via network connectivity.
(CVE-2019-15692)

- TigerVNC version prior to 1.10.1 is vulnerable to heap buffer overflow, which occurs in TightDecoder::FilterGradient. Exploitation of this vulnerability could potentially result into remote code execution. This attack appear to be exploitable via network connectivity. (CVE-2019-15693)

- TigerVNC version prior to 1.10.1 is vulnerable to heap buffer overflow, which could be triggered from DecodeManager::decodeRect. Vulnerability occurs due to the signdness error in processing MemOutStream.
Exploitation of this vulnerability could potentially result into remote code execution. This attack appear to be exploitable via network connectivity. (CVE-2019-15694)

- TigerVNC version prior to 1.10.1 is vulnerable to stack buffer overflow, which could be triggered from CMsgReader::readSetCursor. This vulnerability occurs due to insufficient sanitization of PixelFormat.
Since remote attacker can choose offset from start of the buffer to start writing his values, exploitation of this vulnerability could potentially result into remote code execution. This attack appear to be exploitable via network connectivity. (CVE-2019-15695)

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

This plugin has been deprecated due to Amazon pulling the previously published advisory.

See Also

https://alas.aws.amazon.com/ALAS-2020-1470.html

https://access.redhat.com/security/cve/CVE-2019-15691

https://access.redhat.com/security/cve/CVE-2019-15692

https://access.redhat.com/security/cve/CVE-2019-15693

https://access.redhat.com/security/cve/CVE-2019-15694

https://access.redhat.com/security/cve/CVE-2019-15695

Plugin Details

Severity: High

ID: 144468

File Name: ala_ALAS-2020-1470.nasl

Version: 1.3

Type: local

Agent: unix

Published: 12/19/2020

Updated: 12/23/2020

Dependencies: ssh_get_info.nasl

Risk Information

CVSS Score Source: CVE-2019-15695

VPR

Risk Factor: Medium

Score: 5.9

CVSS v2

Risk Factor: Medium

Base Score: 6.5

Temporal Score: 4.8

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

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

CVSS v3

Risk Factor: High

Base Score: 7.2

Temporal Score: 6.3

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

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

Vulnerability Information

CPE: p-cpe:/a:amazon:linux:tigervnc, p-cpe:/a:amazon:linux:tigervnc-debuginfo, p-cpe:/a:amazon:linux:tigervnc-server, p-cpe:/a:amazon:linux:tigervnc-server-module, cpe:/o:amazon:linux

Required KB Items: Host/local_checks_enabled, Host/AmazonLinux/release, Host/AmazonLinux/rpm-list

Exploit Ease: No known exploits are available

Patch Publication Date: 12/16/2020

Vulnerability Publication Date: 12/26/2019

Reference Information

CVE: CVE-2019-15691, CVE-2019-15692, CVE-2019-15693, CVE-2019-15694, CVE-2019-15695

ALAS: 2020-1470