CVE-2019-25600

HIGH EPSS 48.1%
Published Mar 22, 20263mo ago · Modified Jun 17, 20262w ago
7.1 CVSS 4.0
High
Find Similar
Published Mar 22, 2026 3mo ago
Last Modified Jun 17, 2026 2w ago

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.

CVSS Details

Base Score
7.1
Exploitability
—
Impact
—
Vector string
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction P
Scope X

Threat Intelligence

EPSS Exploit Probability
48.1% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available

Weaknesses 1

CWE-787 Out-of-bounds Write Memory Safety

References 4

  • exploit-db.com https://www.exploit-db.com/exploits/46702
  • uvnc.com https://www.uvnc.com/
  • uvnc.com https://www.uvnc.com/downloads/ultravnc/126-download-ultravnc-1224.html
  • vulncheck.com https://www.vulncheck.com/advisories/ultravnc-viewer-denial-of-service-via-buffer-overflow

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.