EIP-0e1ca3ec

A vulnerability exists within UltraVNC’s “vncviewer.exe” client. Specifically a malicious server may write arbitrary data to arbitrary memory locations through the  in the “rfbServerInitMsg” function upon parsing a long ‘nameLength’ field returned from a nefarious server. An attacker can leverage this in conjunction with other vulnerabilities to execute code in the context of the UltraVNC Viewer process.

Vulnerability Identifiers

• Exodus Intelligence: EIP-0e1ca3ec
• MITRE CVE: PENDING

Vulnerability Metrics

• CVSSv2 Score: 5.8

Vendor References

• https://uvnc.com/downloads/ultravnc/146-ultravnc-1-3-6-0.html

Discovery Credit

• Exodus Intelligence

Disclosure Timeline

• Disclosed to affected vendor: December 8th, 2021
• Disclosed to public: December 16th, 2021

Further Information

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