Tim 'gk^' Nilimaa writes "A serious security hole has been found in PuTY, version 0.54 and before. Simon Tatham and his fellows released PuTTY 0.55 on 2004-08-03 which solves this bug. The bug may allow servers to use PuTTY to act as a machine that you trust, even beforce you verify the hosts key while connecting using SSH2. An attack could be a fact before you know that you have connected to the wrong machine. I (and they) say: upgrade to PuTTY 0.55 - now."