CHMOD is a Linux command for setting file and folder permissions, it is important to set proper file and folder permissions for your phpbb board to avoid important files and data being exploited causing lost of the entire forum. Below list the files and folder in your phpbb forum and the permission level that should be set for each of them :-
- config.php: 666 before install, reset it back to 644 after install
- cache folder: 777
- images/avatars folder: 777
- all the other folders: 755
- all other files: 644
Note: above settings are suitable for servers where php is installed as an apache mod, without the phpsuexec installed. Where the userid executing all the php scripts is the userid that started the apache service. phpsuexec is an apache mod that will run php scripts using individual userids, minimizing the security issues and further tighten the security. There are however pros and cons of running phpsuexec and certain web hosting provider is not setting it as default install on servers.
If you are unsure of your current hosting server setup, you should check with your web host, or simply create a php script with the following code in it, call it on browser to check :-
<? phpinfo(); ?>
After calling the script in browser, locate the Server API , if it says Apache then you do not have phpsuexec installed, if it says CGI then you server has php running with phpsuexec.