Despite Firefly's
security update normal users can still close a thread although they did not started the thread themselves.
Our board has for all registered users configured 'can open/close own threads' set to 'yes'. With this option set, every user is able to use 'Close Thread with Reply' and thus closing the thread. When the option 'can open/close own threads' is set to 'no', the 'Close Thread with Reply' option disappears.
Even tough the hack check for permissions, it checks for the wrong permission, more specific for the permission 'can open/close own threads'. I couldn't find an option 'can open/close threads other threads' anywhere.
Just to let you know. Alas, I can't use the hack right now :-(