CVE-2020-37134
UltraVNC Viewer 1.2.4.0 - 'VNCServer' Denial of Service
- State
- Published
- Severity
- 4.6 Medium
- Published
- Feb 5, 2026
- Updated
- Mar 5, 2026
- Reserved
- Feb 3, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 4.6 Medium | 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 | VulnCheck |
| 3.1 | 7.5 High | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | VulnCheck |
Weaknesses
- CWE-770 Allocation of Resources Without Limits or Throttling
Affected Products
| Product | Versions |
|---|---|
UltraVNC ViewerUltraVNC Team |
|
References
- ExploitDB-48291exploit
- UltraVNC Official Homepageproduct
- VulnCheck Advisory: UltraVNC Viewer 1.2.4.0 - 'VNCServer' Denial of Servicethird-party-advisory
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