Well, not necessarily. It would be much less of a problem if a) a full path name were provided and b) care was taken to ensure that the path name separator had

Well, not necessarily. It would be much less of a problem if a) a full path name were provided and b) care was taken to ensure that the path name separator had not been overridden. As written, or with 'a' but not 'b', there may be a possibility of an attacker manipulating $PATH to cause their own identically-named executable to be invoked with Docker's own privileges.