vulntracker.iovulntracker.io
© 2026 vulntracker.io

CVE-2020-37134

UltraVNC Viewer 1.2.4.0 - 'VNCServer' Denial of Service

HIGH
7.5
CVSS Score
Published: February 5, 2026 at 04:13 PM UTC
Updated: June 17, 2026 at 03:17 AM UTC
1 product affected across 1 vendorVnc Viewer

Using UltraVNC Viewer by UltraVNC Team?

Get instant alerts when new vulnerabilities affect UltraVNC Viewer - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Start FreeSign In
Severity
HIGH7.5
Exploit prediction
EPSS 0.4%
SSVC
PoC

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

References (3)

Exploit
Source: cverecord
https://www.exploit-db.com/exploits/48291
Product
Source: cverecord
https://www.uvnc.com/
Third Party Advisory
Source: cverecord
https://www.vulncheck.com/advisories/ultravnc-viewer-vncserver-denial-of-service

SSVC — Action Prioritization

SSVCPoCAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHVulnCheck
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-770

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Create accountSign in
Free plan, no card