CVE-2018-20749: Critical severity Libvnc Project Libvncserver vulnerability

Published Jan 30, 2019
·
Updated

Last updated 25 August 2025

Other sources

LibVNC before 0.9.12 contains a heap out-of-bounds write vulnerability in libvncserver/rfbserver.c. The fix for CVE-2018-15127 was incomplete.

Launchpad

Affected Software

33 affected componentsFixes available
Libvnc Project Libvncserver<0.9.12
Canonical Ubuntu Linux=14.04
Canonical Ubuntu Linux=16.04
Canonical Ubuntu Linux=16.04
Canonical Ubuntu Linux=18.04
Canonical Ubuntu Linux=18.10
Debian Debian Linux=8.0
Debian Debian Linux=9.0
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
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
debian/libvncserver
0.9.13+dfsg-2+deb11u10.9.14+dfsg-1+deb12u10.9.15+dfsg-1+deb13u10.9.15+dfsg-6

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 LibVNC to a version that resolves this vulnerability.

    Fixed in 0.9.12
  3. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Patch CVE-2018-15127

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
Feb 18, 2026
Data Sourced
via Ubuntu·07:58 PM
RemedyDescriptionSeverityAffected Software
Jul 5, 2026
Data Sourced
via Debian·02:49 AM
DescriptionAffected Software
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Frequently Asked Questions

1

What is CVE-2018-20749?

CVE-2018-20749 is a heap out-of-bounds write vulnerability in LibVNC before 0.9.12.

2

What is the severity of CVE-2018-20749?

The severity of CVE-2018-20749 is critical with a CVSS score of 9.8.

3

How does CVE-2018-20749 affect LibVNC?

CVE-2018-20749 affects LibVNC before version 0.9.12.

4

How can I fix CVE-2018-20749?

To fix CVE-2018-20749, you should update LibVNC to version 0.9.12 or later.

5

Where can I find more information about CVE-2018-20749?

You can find more information about CVE-2018-20749 at the following references: [1] [2] [3].

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