Client crash via oversized username input

Buffer overflow in Core FTP Lite 1.3c Build 1437 allows local users to crash the client by entering an oversized username. The username text box accepts a 7,000-character string without enforcing its destination buffer's size, overflowing the buffer as the field processes the input. Reaching the flaw requires active interaction with the Windows GUI; the published proof of concept demonstrates a client crash, not code execution or data exposure.