CVE-2022-23967

In TightVNC 1.3.10, there is an integer signedness error and resultant heap-based buffer overflow in InitialiseRFBConnection in rfbproto.c (for the vncviewer component). There is no check on the size given to malloc, e.g., -1 is accepted. This allocates a chunk of size zero, which will give a heap pointer. However, one can send 0xffffffff bytes of data, which can have a DoS impact or lead to remote code execution.

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[Vulnerability Type] Buffer Overflow

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[Vendor of Product] TightVNC

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[Affected Product Code Base] vncviewer - 1.3.10

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[Affected Component] file : rfbproto.c, function : InitialiseRFBConnection , line of code : 307

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[Attack Type] Remote

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[Impact Denial of Service] true

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[Attack Vectors] You just need to setup a fake server, to interact with the vulnerable client.

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[Discoverer] Maher Azzouzi

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[Reference] https://www.tightvnc.com/licensing-server-x11.php

Use CVE-2022-23967.