Correct CHMOD permissions help to secure your site, the wrong CHMOD permissions will make it vulnerable to hackers, so it is important that you learn the basics & also how to change any unsecure permission settings. This CHMOD Calculator will help you get the hang of it, and be here in-case you ever forget. There are three types that can get to a file if you allow them to:
- The Owner (You)
- The Group
NOTE: CHMOD permission setting of 777 will allow anyone to access (& do what they want with) your files – therefore it is not recommended.
(Permission settings of 655 or 644 are commonly used by many website components as they provide some security whilst still allowing the component to function properly.)
Default modes if you upload a file to the server (and have changed nothing) are:
All Files that are not scripts or directories: 644
All directories and anything that looks like a script (.cgi and .pl files for example): 755