FreePBX is an open source IP PBX. Prior to 16.0.47 and 17.0.30, the FreePBX Framework module permits a crafted backup to restore the hidden AUTHTYPE setting with the value none through runRestore() in amp_conf/htdocs/admin/libraries/Builtin/Restore.php. An authenticated user with sufficient backup-restore access or write access to backup files can thereby disable FreePBX authentication during restoration, bypassing the user-interface removal of AUTHTYPE=none. This issue is fixed in versions 16.0.47 and 17.0.30.