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.
- Exodus Intelligence: EIP-0e1ca3ec
- MITRE CVE: PENDING
- CVSSv2 Score: 5.8
- Exodus Intelligence
- Disclosed to affected vendor: December 8th, 2021
- Disclosed to public: December 16th, 2021
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