UltraVNC Viewer 1.2.4.0 contains a denial of service vulnerability that allows attackers to crash the application by manipulating VNC Server input. Attackers can generate a malformed 256-byte payload and paste it into the VNC Server connection dialog to trigger an application crash.
History

Thu, 05 Feb 2026 16:30:00 +0000

Type Values Removed Values Added
Description UltraVNC Viewer 1.2.4.0 contains a denial of service vulnerability that allows attackers to crash the application by manipulating VNC Server input. Attackers can generate a malformed 256-byte payload and paste it into the VNC Server connection dialog to trigger an application crash.
Title UltraVNC Viewer 1.2.4.0 - 'VNCServer' Denial of Service
Weaknesses CWE-770
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

cvssV4_0

{'score': 4.6, 'vector': 'CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-02-05T16:13:36.934Z

Reserved: 2026-02-03T16:27:45.306Z

Link: CVE-2020-37134

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-02-05T17:16:08.690

Modified: 2026-02-05T17:16:08.690

Link: CVE-2020-37134

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.