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Fencer Intel
high 7.5

CVE-2018-20022 json

LibVNC before 2f5b2ad1c6c99b1ac6482c95844a84d66bb52838 contains multiple weaknesses CWE-665: Improper Initialization vulnerability in VNC c…

published 2018-12-19 7 y ago modified 2026-06-17 4 mo ago also EUVD-2018-12600

cvss
7.5
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
2.9%
EPSS 2.9% chance of exploitation in 30 days, percentile 87%
public exploits
0
none known

Summary

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

Patch / fix

  • libvnc_project libvncserver 0.9.12
  • ssvnc Debian 14, Debian 13, Debian 12 1.0.29-5
  • veyon Debian 13, Debian 12 4.1.4+repack1-1
  • tightvnc Debian 14, Debian 13, Debian 12 1:1.3.9-9.1
  • libvncserver Debian 14, Debian 13, Debian 12 0.9.11+dfsg-1.2

debian advisories DEBIAN-CVE-2018-20022

  • italc Ubuntu 16.04 LTS 1:2.0.2+dfsg1-4ubuntu0.1
  • italc Ubuntu 18.04 LTS 1:3.0.3+dfsg1-3ubuntu0.1
  • ssvnc Ubuntu 16.04 LTS 1.0.29-2+deb8u1build0.16.04.1
  • libvncserver Ubuntu 14.04 LTS 0.9.9+dfsg-1ubuntu1.4
  • libvncserver Ubuntu 16.04 LTS 0.9.10+dfsg-3ubuntu0.16.04.3
  • libvncserver Ubuntu 18.04 LTS 0.9.11+dfsg-1ubuntu1.1
  • tightvnc Ubuntu Pro 14.04 LTS 1.3.9-6.5+deb8u1build0.14.04.1~esm1

ubuntu advisories UBUNTU-CVE-2018-20022

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • LibVNCServer SLES 12 SP4, SLES 12 SP3, SLES 12 SP2-BCL +11 more 0.9.9-17.8.1
  • LibVNCServer SLE Workstation Extension 15, SLE Module for Package Hub 15 0.9.10-4.3.1
  • LibVNCServer SLES for SAP 11 SP4, SLES 11 SP4, SLES 11 SP3-TERADATA +3 more 0.9.1-160.6.1

suse advisories SUSE-SU-2019:0060-2SUSE-SU-2019:0080-1SUSE-SU-2019:13927-1SUSE-SU-2019:0060-1

  • LibVNCServer openSUSE Leap 15.0 0.9.10-lp150.3.3.1

opensuse advisories openSUSE-SU-2019:0053-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2018-20022 updated cvss 5.4

libvncserver: Improper initialization in VNC client code allows for information disclosure

  • Red Hat Enterprise Linux 6 libvncserver
    affected: no fix planned “Will not fix”
  • Red Hat Enterprise Linux 7 libvncserver
    affected: no fix available “Fix deferred”
  • Red Hat Enterprise Linux 8 libvncserver
    affected: no fix planned “Will not fix”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

2.94% chance of exploitation in the next 30 days, higher than 87% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.0 7.5 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:P/I:N/A:N

Affected products

  • n/a LibVNC

Classification

Weakness

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.