CVE-2018-20020: Critical severity Libvnc Project Libvncserver vulnerability
Last updated 11 July 2025
Other sources
LibVNC before commit 7b1ef0ffc4815cab9a96c7278394152bdc89dc4d contains heap out-of-bound write vulnerability inside structure in VNC client code that can result remote code execution
— Launchpad
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
debian/libvncserverto 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 - Upgrade
Upgrade
debian/ssvncto 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 - Upgrade
Upgrade
debian/veyonto 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 - Upgrade
Upgrade
LibVNCto a version that resolves this vulnerability.Patch 7b1ef0ffc4815cab9a96c7278394152bdc89dc4d
Event History
Frequently Asked Questions
What is the severity of CVE-2018-20020?
The severity of CVE-2018-20020 is critical.
What is the vulnerability ID for LibVNC before commit 7b1ef0ffc4815cab9a96c7278394152bdc89dc4d?
The vulnerability ID for LibVNC before commit 7b1ef0ffc4815cab9a96c7278394152bdc89dc4d is CVE-2018-20020.
How can the heap out-of-bound write vulnerability in LibVNC before commit 7b1ef0ffc4815cab9a96c7278394152bdc89dc4d result in remote code execution?
The heap out-of-bound write vulnerability in LibVNC before commit 7b1ef0ffc4815cab9a96c7278394152bdc89dc4d can allow attackers to execute code remotely by exploiting the vulnerability in the VNC client code.
Which software versions are affected by CVE-2018-20020?
The affected software versions for CVE-2018-20020 include Ubuntu tightvnc 1:1.3.9-6.5+, Ubuntu libvncserver 0.9.11+dfsg-1ubuntu1.1, Ubuntu libvncserver 0.9.11+dfsg-1.1ubuntu0.1, Ubuntu libvncserver 0.9.11+dfsg-1.2, Ubuntu libvncserver 0.9.10+dfsg-3ubuntu0.16.04.3, Ubuntu libvncserver 0.9.9+dfsg-1ubuntu1.4, Ubuntu italc 1:3.0.3+dfsg1-3ubuntu0.1, Ubuntu italc 1:3.0.3+dfsg1-1+, Ubuntu italc 1:2.0.2+dfsg1-2+, Ubuntu italc 1:2.0.2+dfsg1-4ubuntu0.1, Ubuntu ssvnc 1.9.29-2+, Ubuntu ssvnc 1.0.29-2+, Debian libvncserver 0.9.11+dfsg-1.3+deb10u4, Debian libvncserver 0.9.11+dfsg-1.3+deb10u5, Debian libvncserver 0.9.13+dfsg-2+deb11u1, Debian libvncserver 0.9.14+dfsg-1, Debian ssvnc 1.0.29-4+deb10u1, Debian ssvnc 1.0.29-5, Debian ssvnc 1.0.29-6.
How can the vulnerability in LibVNC before commit 7b1ef0ffc4815cab9a96c7278394152bdc89dc4d be fixed?
To fix the vulnerability in LibVNC before commit 7b1ef0ffc4815cab9a96c7278394152bdc89dc4d, it is recommended to update to a version that includes the fix, such as commit 7b1ef0ffc4815cab9a96c7278394152bdc89dc4d.