Control channels with -n cause the bot to be vulnerable

[zuzak]

If the control channel is set to -n, any user can issue privileged commands to it without being on the channel. This means that any user could e.g. quit the bot without authentication.

The bot should either use a different authentication mechanism, or should refuse to execute privileged commands if the nick is not in channel. This could be done by keeping tracks of both nicknames and nickname changes in the control channel via the names event.