MyProxy 5.0 through 5.2, as used in Globus Toolkit 5.0.0 through 5.0.2, does not properly verify the (1) hostname or (2) identity in the X.509 certificate for the myproxy-server, which allows remote attackers to spoof the server and conduct man-in-the-middle (MITM) attacks via a crafted certificate when executing (a) myproxy-logon or (b) myproxy-get-delegation.