there is a good difference between freezing the rcon service and retrieving the rcon password.
in the first case the only "solution" is disabling the half-second check:
http://aluigi.org/patches/q3rconz.lpatchthe downside is that without this check the brute forcing attacks are fasters, so you MUST choose a strong rcon password
if you have problems with people retrieving the rcon password you must:
- disable voting
- set sv_allowdownload 0
if you use mods they could be bugged (for example cvars expansion) and in that case I don't have solutions.