UltraVNC Viewer 1.2.2.4 contains a denial of service vulnerability that allows attackers to crash the application by supplying an oversized string to the VNC Server input field. Attackers can paste a malicious string containing 256 repeated characters into the VNC Server field and click Connect to trigger a buffer overflow that crashes the viewer.
History

Sun, 22 Mar 2026 13:45:00 +0000

Type Values Removed Values Added
Description UltraVNC Viewer 1.2.2.4 contains a denial of service vulnerability that allows attackers to crash the application by supplying an oversized string to the VNC Server input field. Attackers can paste a malicious string containing 256 repeated characters into the VNC Server field and click Connect to trigger a buffer overflow that crashes the viewer.
Title UltraVNC Viewer 1.2.2.4 Denial of Service via Buffer Overflow
Weaknesses CWE-787
References
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H'}

cvssV4_0

{'score': 7.1, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-03-22T13:38:36.517Z

Reserved: 2026-03-22T12:59:37.342Z

Link: CVE-2019-25600

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-03-22T14:16:27.343

Modified: 2026-03-22T14:16:27.343

Link: CVE-2019-25600

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.