Call of Duty versions 1.4 and below use some anti-buffer-overflow checks that automatically shutdown the game if they find a too big input. The result is that a query or a reply containing over 1024 chars is able to exploit this protection causing the immediate stop of the game.
9583108fdf5efbc20a5366f2c6a5e031e725730003b709353c1d34e9997346f1
Proof of concept exploit for Call of Duty versions 1.4 and below that makes use of a denial of service vulnerability.
b8ddb5cf9cad3d53397ea5b472ac427b2bf469e3d1f577eed36f7a8721fd2021