UltraVNC revision 1207 has multiple out-of-bounds access vulnerabilities connected with improper usage of ClientConnection::Copybuffer function in VNC client code, which can potentially result in code execution. This attack appears to be exploitable via network connectivity. User interaction is required to trigger these vulnerabilities. These vulnerabilities have been fixed in revision 1208.
The product reads or writes to a buffer using an index or pointer that references a memory location after the end of the buffer.
The product reads data past the end, or before the beginning, of the intended buffer.