CVE-2018-20022: High severity Libvnc Project Libvncserver vulnerability

Published Dec 19, 2018
·
Updated

Last updated 11 July 2025

Other sources

LibVNC before 2f5b2ad1c6c99b1ac6482c95844a84d66bb52838 contains multiple weaknesses CWE-665: Improper Initialization vulnerability in VNC client code that allows attacker to read stack memory and can be abuse for information disclosure. Combined with another vulnerability, it can be used to leak stack memory layout and in bypassing ASLR

Launchpad

Affected Software

11 affected componentsFixes available
Libvnc Project Libvncserver<0.9.12
Debian Debian Linux=8.0
Debian Debian Linux=9.0
Canonical Ubuntu Linux=14.04
Canonical Ubuntu Linux=16.04
Canonical Ubuntu Linux=18.04
Canonical Ubuntu Linux=18.10
debian/libvncserver
0.9.13+dfsg-2+deb11u10.9.14+dfsg-1+deb12u10.9.15+dfsg-1+deb13u10.9.15+dfsg-6
debian/ssvnc
1.0.29-51.0.29-61.0.29-6.11.0.29-7
debian/tightvnc
1:1.3.10-31:1.3.10-71:1.3.10-91:1.3.10-11
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/ssvnc to a version that resolves this vulnerability.

    Fixed in 1.0.29-5Fixed in 1.0.29-6Fixed in 1.0.29-6.1Fixed in 1.0.29-7
  3. Upgrade

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

    Fixed in 1:1.3.10-3Fixed in 1:1.3.10-7Fixed in 1:1.3.10-9Fixed in 1:1.3.10-11
  4. 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
  5. Upgrade

    Upgrade LibVNC to a version that resolves this vulnerability.

    Patch 2f5b2ad1c6c99b1ac6482c95844a84d66bb52838

Event History

Dec 19, 2018
CVE Published
via MITRE·04:00 PM
Data Sourced
via MITRE·04:00 PM
DescriptionWeakness
Data Sourced
via NVD·04:29 PM
DescriptionSeverityWeaknessAffected Software
Jan 11, 2024
Data Sourced
via Launchpad·10:58 PM
Description
Jul 13, 2025
Data Sourced
via Ubuntu·03:57 AM
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-2018-20022?

CVE-2018-20022 is a vulnerability in LibVNC that allows an attacker to read stack memory and potentially leak sensitive information.

2

How severe is CVE-2018-20022?

CVE-2018-20022 has a severity rating of 7.5 (high).

3

Which software versions are affected by CVE-2018-20022?

CVE-2018-20022 affects LibVNC before version 2f5b2ad1c6c99b1ac6482c95844a84d66bb52838.

4

How can I fix the CVE-2018-20022 vulnerability?

To fix the CVE-2018-20022 vulnerability, update to LibVNC version 2f5b2ad1c6c99b1ac6482c95844a84d66bb52838 or apply the necessary patches.

5

Where can I find more information about CVE-2018-20022?

You can find more information about CVE-2018-20022 at the following references: [GitHub Issue](https://github.com/LibVNC/libvncserver/issues/252), [GitHub Commit](https://github.com/LibVNC/libvncserver/commit/2f5b2ad1c6c99b1ac6482c95844a84d66bb52838), [Kaspersky Advisory](https://ics-cert.kaspersky.com/advisories/klcert-advisories/2018/12/19/klcert-18-032-libvnc-multiple-memory-leaks/).

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