PT-2020-2982 · Libvnc+7 · Libvncserver+7

Published 2019-08-30 · Updated 2022-03-09 · CVE-2020-14405

Positive Technologies (AI Summary)

CVSS v3.1

6.5

Medium

Base vector

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

Name of the Vulnerable Software and Affected Versions LibVNCServer versions prior to 0.9.13

Description The issue is related to the libvncclient/rfbproto.c component of the LibVNCServer library, where there is an unlimited memory allocation when accessing TextChat. This could allow a remote attacker to impact the confidentiality, integrity, and availability of protected information. The problem arises because libvncclient/rfbproto.c does not limit the size of TextChat.

Recommendations For versions prior to 0.9.13, update to version 0.9.13 or later to resolve the issue. As a temporary workaround, consider restricting access to the TextChat feature until the update is applied.

Fix

Allocation of Resources Without Limits

Weakness Enumeration

CWE-770

Related Identifiers

ALSA-2021:1811

ALT-PU-2019-2585

ALT-PU-2019-2662

ALT-PU-2020-2671

ALT-PU-2020-2694

BDU:2020-03149

CESA-2021_1811

CVE-2020-14405

DLA-2264-1

DLA-2347-1

MGASA-2020-0280

RHSA-2021:1811

RHSA-2021_1811

RLSA-2021:1811

USN-4434-1

Affected Products

Alt Linux

Almalinux

Centos

Libvncserver

Linuxmint

Red Hat

Rocky Linux

Ubuntu

References · 57

• https://github.com/LibVNC/libvncserver/commit/8937203441ee241c4ace85da687b7d6633a12365 · Patch
• https://ubuntu.com/security/CVE-2020-14396 · Vendor Advisory
• https://errata.rockylinux.org/RLSA-2021:1811 · Vendor Advisory
• https://linux.oracle.com/errata/ELSA-2021-1811.html · Vendor Advisory
• https://advisories.mageia.org/MGASA-2020-0280.html · Security Note
• https://errata.almalinux.org/8/ALSA-2021-1811.html · Vendor Advisory
• https://osv.dev/vulnerability/USN-4434-1 · Vendor Advisory
• https://osv.dev/vulnerability/MGASA-2020-0280 · Vendor Advisory
• https://ubuntu.com/security/CVE-2019-20840 · Vendor Advisory
• https://ubuntu.com/security/CVE-2020-14405 · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2020-14405 · Vendor Advisory
• https://wiki.astralinux.ru/pages/viewpage.action?pageId=47416144 · Vendor Advisory
• https://osv.dev/vulnerability/RLSA-2021:1811 · Vendor Advisory
• https://ubuntu.com/security/CVE-2020-14398 · Vendor Advisory
• https://osv.dev/vulnerability/ALSA-2021:1811 · Vendor Advisory