Denial of Service Vulnerability in UltraVNC Launcher by UltraVNC
CVE-2020-37133

6.7MEDIUM

Key Information:

Vendor

Ultravnc Team

Status
Ultravnc Launcher
Vendor
CVE Published:
5 February 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2020-37133?

The UltraVNC Launcher 1.2.4.0 is susceptible to a denial of service vulnerability due to improper handling of input in the Repeater Host configuration field. Attackers can exploit this flaw by entering a maliciously crafted string of over 300 characters, compelling the application to crash. This vulnerability could disrupt services and impact user experience significantly.

Affected Version(s)

UltraVNC Launcher 1.2.4.0

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2020-37133 - Proof of Concept

References

https://www.exploit-db.com/exploits/48288
exploit
https://www.uvnc.com/
product
https://www.vulncheck.com/advisories/ultravnc-launcher-re...
third-party-advisory

CVSS V4

Score:
6.7
Severity:
MEDIUM
Confidentiality:
High
Integrity:
None
Availability:
None
Attack Vector:
Local
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
Unknown

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

chuyreds
.