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Fencer Vulns
medium 5.4

CVE-2020-14403 json

An issue was discovered in LibVNCServer before 0.9.13.

published 2020-06-17 6 y ago modified 2026-06-17 4 mo ago also EUVD-2020-6542

cvss
5.4
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.6%
EPSS 1.6% chance of exploitation in 30 days, percentile 76%
public exploits
0
none known

Summary

An issue was discovered in LibVNCServer before 0.9.13. libvncserver/hextile.c allows out-of-bounds access via encodings.

Patch / fix

  • siemens simatic_itc1500_firmware 3.2.1.0
  • siemens simatic_itc1500_pro_firmware 3.2.1.0
  • siemens simatic_itc1900_firmware 3.2.1.0
  • siemens simatic_itc1900_pro_firmware 3.2.1.0
  • siemens simatic_itc2200_firmware 3.2.1.0
  • siemens simatic_itc2200_pro_firmware 3.2.1.0
  • libvncserver Debian 14, Debian 13, Debian 12 0.9.13+dfsg-1

debian advisories DEBIAN-CVE-2020-14403

  • vino Ubuntu 16.04 LTS 3.8.1-0ubuntu9.3
  • vino Ubuntu 18.04 LTS 3.22.0-3ubuntu1.1
  • vino Ubuntu 20.04 LTS 3.22.0-5ubuntu2.1
  • libvncserver Ubuntu 16.04 LTS 0.9.10+dfsg-3ubuntu0.16.04.5
  • libvncserver Ubuntu 18.04 LTS 0.9.11+dfsg-1ubuntu1.3
  • libvncserver Ubuntu 20.04 LTS 0.9.12+dfsg-9ubuntu0.2

ubuntu advisories UBUNTU-CVE-2020-14403

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 for SAP 12 SP5, SLES for SAP 12 SP4, SLES for SAP 12 SP3 +15 more 0.9.9-17.31.1

suse advisories SUSE-SU-2020:2167-1

  • libvncserver Alpine 3.24, Alpine 3.23, Alpine 3.22 +10 more 0.9.13-r0

alpine advisories ALPINE-CVE-2020-14403

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

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-2020-14403 updated cvss 5.4

libvncserver: libvncserver/hextile.c allows out-of-bounds access via encodings

  • Red Hat Enterprise Linux 6 vino, libvncserver
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 7 vino, libvncserver Red Hat Enterprise Linux 8 vino, libvncserver
    affected: no fix available “Fix deferred”

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

cisa ICSA-21-350-12 updated cvss 5.4

Siemens SIMATIC ITC

  • Siemens SIMATIC ITC1500 V3 <V3.2.1.0 Siemens SIMATIC ITC1500 V3 PRO <V3.2.1.0 Siemens SIMATIC ITC1900 V3 <V3.2.1.0 Siemens SIMATIC ITC1900 V3 PRO <V3.2.1.0 Siemens SIMATIC ITC2200 V3 <V3.2.1.0 Siemens SIMATIC ITC2200 V3 PRO <V3.2.1.0
    affected: fixed in V3.2.1.0, mitigation support.industry.siemens.com

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

Exploit prediction

1.61% chance of exploitation in the next 30 days, higher than 76% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 5.4 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:L
NVD 2.0 5.5 AV:N/AC:L/Au:S/C:P/I:N/A:P

Classification

Weakness

References

Sources

Fencer Vulns 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.