CVE-2020-14403

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

Published: 2020-06-17 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2020-14403 is rated Moderate Risk (49.9/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.33%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2020-14403

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-28 1.11% 1.33% +0.22%
2 2025-12-28 0.97% 1.11% +0.14%
3 2025-12-27 — 0.97% —

Full EPSS history (18 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2020-14403

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.4 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:L Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 2.8 2.5 [email protected]
5.5 2.0 MEDIUM
AV:N/AC:L/Au:S/C:P/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:S)
A single authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.0 4.9 [email protected]

Weakness enumeration for CVE-2020-14403

OS Trackers for CVE-2020-14403

vendor priority summary link
alpine medium CVE-2020-14403: 1 source package rows (libvncserver); 15 state rows across 9 repos (3.10-main, 3.11-main, 3.17-community, 3.18-community, 3.19-community, 3.20-community, 3.21-community, 3.22-community, edge-community); fixed 7, open 8. https://security.alpinelinux.org/vuln/CVE-2020-14403
debian not yet assigned CVE-2020-14403 not yet assigned priority: Debian including 1 source packages (libvncserver), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2020-14403
redhat low — https://access.redhat.com/security/cve/CVE-2020-14403
suse medium CVE-2020-14403 severity moderate: SUSE including 10 source package names (LibVNCServer-devel-0.9.13-3.1, LibVNCServer-devel-0.9.9-17.31.1, …), 54 product×package rows across 27 product lines (HPE Helion OpenStack 8, SUSE Enterprise Storage 5, … (27 product lines)): Fixed 54. https://www.suse.com/security/cve/CVE-2020-14403/
ubuntu medium CVE-2020-14403 medium priority: Ubuntu including 4 source packages (libvncserver, veyon, vino, x11vnc), 67 status rows across 17 suites (bionic, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): not-affected 20, ignored 17, released 17, needs-triage 8, DNE 5. https://ubuntu.com/security/CVE-2020-14403

Affected software / configurations for CVE-2020-14403

Vendor Product Version Raw CPE
libvnc_project libvncserver <= 0.9.12 cpe:2.3:a:libvnc_project:libvncserver:*:*:*:*:*:*:*:*
canonical ubuntu_linux 14.04 cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 16.04 cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:*
canonical ubuntu_linux 16.04 cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 18.04 cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*
canonical ubuntu_linux 18.10 cpe:2.3:o:canonical:ubuntu_linux:18.10:*:*:*:*:*:*:*
canonical ubuntu_linux 20.04 cpe:2.3:o:canonical:ubuntu_linux:20.04:*:*:*:lts:*:*:*
debian debian_linux 8.0 cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
siemens simatic_itc1500_firmware >= 3.0.0.0, < 3.2.1.0 cpe:2.3:o:siemens:simatic_itc1500_firmware:*:*:*:*:*:*:*:*
siemens simatic_itc1500_pro_firmware >= 3.0.0.0, < 3.2.1.0 cpe:2.3:o:siemens:simatic_itc1500_pro_firmware:*:*:*:*:*:*:*:*
siemens simatic_itc1900_firmware >= 3.0.0.0, < 3.2.1.0 cpe:2.3:o:siemens:simatic_itc1900_firmware:*:*:*:*:*:*:*:*
siemens simatic_itc1900_pro_firmware >= 3.0.0.0, < 3.2.1.0 cpe:2.3:o:siemens:simatic_itc1900_pro_firmware:*:*:*:*:*:*:*:*
siemens simatic_itc2200_firmware >= 3.0.0.0, < 3.2.1.0 cpe:2.3:o:siemens:simatic_itc2200_firmware:*:*:*:*:*:*:*:*
siemens simatic_itc2200_pro_firmware >= 3.0.0.0, < 3.2.1.0 cpe:2.3:o:siemens:simatic_itc2200_pro_firmware:*:*:*:*:*:*:*:*

References for CVE-2020-14403

cvelogic Threat Intelligence