CVE-2018-20748: Critical severity Libvnc Project Libvncserver vulnerability

Published Jan 30, 2019
·
Updated

Last updated 11 July 2025

Other sources

LibVNC before 0.9.12 contains multiple heap out-of-bounds write vulnerabilities in libvncclient/rfbproto.c. The fix for CVE-2018-20019 was incomplete.

Launchpad

Affected Software

32 affected componentsFixes available
Libvnc Project Libvncserver<0.9.12
Debian Debian Linux=8.0
Canonical Ubuntu Linux=14.04
Canonical Ubuntu Linux=16.04
Canonical Ubuntu Linux=18.04
Canonical Ubuntu Linux=18.10
Siemens Simatic Itc1500 Firmware>=3.0.0.0<3.2.1.0
Siemens Simatic Itc1500
Siemens Simatic Itc1500 Pro Firmware>=3.0.0.0<3.2.1.0
Siemens Simatic Itc1500 Pro
Siemens Simatic Itc1900 Firmware>=3.0.0.0<3.2.1.0
Siemens Simatic Itc1900
Siemens Simatic Itc1900 Pro Firmware>=3.0.0.0<3.2.1.0
Siemens Simatic Itc1900 Pro
Siemens Simatic Itc2200 Firmware>=3.0.0.0<3.2.1.0
Siemens Simatic Itc2200
Siemens Simatic Itc2200 Pro Firmware>=3.0.0.0<3.2.1.0
Siemens Simatic Itc2200 Pro
All of the following
Siemens Simatic Itc1500 Firmware>=3.0.0.0<3.2.1.0
Siemens Simatic Itc1500
All of the following
Siemens Simatic Itc1500 Pro Firmware>=3.0.0.0<3.2.1.0
Siemens Simatic Itc1500 Pro
All of the following
Siemens Simatic Itc1900 Firmware>=3.0.0.0<3.2.1.0
Siemens Simatic Itc1900
All of the following
Siemens Simatic Itc1900 Pro Firmware>=3.0.0.0<3.2.1.0
Siemens Simatic Itc1900 Pro
All of the following
Siemens Simatic Itc2200 Firmware>=3.0.0.0<3.2.1.0
Siemens Simatic Itc2200
All of the following
Siemens Simatic Itc2200 Pro Firmware>=3.0.0.0<3.2.1.0
Siemens Simatic Itc2200 Pro
debian/libvncserver
0.9.13+dfsg-2+deb11u10.9.14+dfsg-1+deb12u10.9.15+dfsg-1+deb13u10.9.15+dfsg-6
debian/veyon
4.5.3+repack1-14.7.5+repack1-14.9.5+repack1-24.9.7+repack1-1.1

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade debian/libvncserver to a version that resolves this vulnerability.

    Fixed in 0.9.13+dfsg-2+deb11u1Fixed in 0.9.14+dfsg-1+deb12u1Fixed in 0.9.15+dfsg-1+deb13u1Fixed in 0.9.15+dfsg-6
  2. Upgrade

    Upgrade debian/veyon to a version that resolves this vulnerability.

    Fixed in 4.5.3+repack1-1Fixed in 4.7.5+repack1-1Fixed in 4.9.5+repack1-2Fixed in 4.9.7+repack1-1.1
  3. Upgrade

    Upgrade LibVNC to a version that resolves this vulnerability.

    Fixed in 0.9.12

Event History

Jan 30, 2019
CVE Published
via MITRE·06:00 PM
Data Sourced
via MITRE·06:00 PM
Description
Data Sourced
via NVD·06:29 PM
RemedyDescriptionSeverityWeaknessAffected Software
Jan 11, 2024
Data Sourced
via Launchpad·11:00 PM
Description
Jul 25, 2025
Data Sourced
via Ubuntu·04:14 AM
RemedyDescriptionSeverityAffected Software
Jul 7, 2026
Data Sourced
via Debian·02:53 AM
DescriptionAffected Software
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Frequently Asked Questions

1

What is the vulnerability ID for this vulnerability?

The vulnerability ID for this vulnerability is CVE-2018-20748.

2

What is the severity of CVE-2018-20748?

The severity of CVE-2018-20748 is critical, with a severity value of 9.8.

3

Which software is affected by CVE-2018-20748?

The software affected by CVE-2018-20748 includes LibVNC before version 0.9.12, italc package on Ubuntu, libvncserver package on Ubuntu and Debian, and veyon package on Debian.

4

What is the fix for CVE-2018-20748?

The fix for CVE-2018-20748 can be found in the following commits: c5ba3fee85a7ecbbca1df5ffd46d32b92757bc2a, e34bcbb759ca5bef85809967a268fdf214c1ad2c, and c2c4b81e6cb3b485fb1ec7ba9e7defeb889f6ba7.

5

What is the Common Vulnerabilities and Exposures (CVE) index?

The Common Vulnerabilities and Exposures (CVE) index is a system used to uniquely identify vulnerabilities in software and systems. It provides a standardized naming scheme for vulnerabilities and is widely used in the cybersecurity industry.

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