Allaire has released a patch for this issue. Allaire Forums 2.0.5
Allaire forumfixThe template files were created to replace the existing files on your system. It is recommended you back up your existing data before over-writing or replacing any files. You will also need to modify these files to reflect any personal coding changes you have made to your existing Forums installatio http://download.allaire.com/patches/ASB00-07forumfix.zip
Allaire Forums 2.0.5 may allow users to view, and post to secure conferences through unsecure conferences or via email, because of improper handling of the "rightAccessAllForums" variable.
To fix resolve this vulnerability, install the Allaire Forums 2.0.5 Security Patch or upgrade to Allaire Forums version 2.0.6 or higher. However, if upgrading is not possible, remove the following template files (this may break some Forums functionality): Application.cfm, Conf_ThreadList.cfm, MessageEdit_Action.cfm, Search_Results.cfm, _NewSession.cfm