CVE-2019-20840: High severity libvncserver vulnerability

Published Jun 17, 2020
·
Updated

An issue was discovered in LibVNCServer before 0.9.13. libvncserver/wsdecode.c can lead to a crash because of unaligned accesses in hybiReadAndDecode.

Affected Software

35 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
Canonical Ubuntu Linux=20.04
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
openSUSE Leap=15.2
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-10.9.15+dfsg-1

Event History

Jun 17, 2020
CVE Published
via MITRE·03:11 PM
Data Sourced
via MITRE·03:11 PM
Description
Jan 11, 2024
Data Sourced
via Launchpad·11:27 PM
Description
Sep 16, 2024
Data Sourced
via Ubuntu·02:14 AM
RemedyDescriptionSeverityAffected Software
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Frequently Asked Questions

1

What is CVE-2019-20840?

CVE-2019-20840 is a vulnerability discovered in LibVNCServer before version 0.9.13 that can lead to a crash due to unaligned accesses in hybiReadAndDecode.

2

How severe is CVE-2019-20840?

CVE-2019-20840 has a severity rating of 7.5, which is considered high.

3

Which software versions are affected by CVE-2019-20840?

The affected software versions include libvncserver 0.9.11+dfsg-1.3+deb10u4 to 0.9.11+dfsg-1.3+deb10u5, 0.9.13+dfsg-2+deb11u1, and 0.9.14+dfsg-1.

4

How can I fix CVE-2019-20840?

To fix CVE-2019-20840, update the libvncserver package to version 0.9.13 or higher.

5

Where can I find more information about CVE-2019-20840?

You can find more information about CVE-2019-20840 on the CVE Mitre website (https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-20840) and the LibVNCServer GitHub page (https://github.com/LibVNC/libvncserver/compare/LibVNCServer-0.9.12...LibVNCServer-0.9.13).

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