CVE-2020-37134

medium

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.

References

https://www.vulncheck.com/advisories/ultravnc-viewer-vncserver-denial-of-service

https://www.uvnc.com/

https://www.exploit-db.com/exploits/48291

Details

Source: Mitre, NVD

Published: 2026-02-05

Updated: 2026-02-05

Risk Information

CVSS v2

Base Score: 7.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C

Severity: High

CVSS v3

Base Score: 7.5

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Severity: High

CVSS v4

Base 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

Severity: Medium

EPSS

EPSS: 0.00028