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.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Attack Requirements
None
No additional conditions
Privileges Required
None
No privileges needed
User Interaction
Passive
Minimal interaction
Impact Assessment
Confidentiality
None
No data leak
Integrity
None
No data modification
Availability
High
Complete denial of service
CVSS Vector v4.0
Weakness Type (CWE)
References 4
https://www.exploit-db.com/exploits/46702
disclosure@vulncheck.com
https://www.uvnc.com/
disclosure@vulncheck.com
https://www.uvnc.com/downloads/ultravnc/126-download-ultravnc-1224.html
disclosure@vulncheck.com
https://www.vulncheck.com/advisories/ultravnc-viewer-denial-of-service-via-buff…
disclosure@vulncheck.com