File Permissions & Access

File Permissions & Access

Linux and UNIX are multi-user operating system which can be accessed by many users simultaneously. Linux can also be used in mainframes and servers without any modifications. Although there are already a lot of good security features built into Linux-based systems, one very important potential vulnerability can exist when local access is granted. But this raises security concerns as an unsolicited or malign user can corrupt, change or remove crucial data.

Linux divides authorization into 2 levels :
1 .   Basic File Permissions
2 .   Permission Groups
» Each file and directory has three user based permission groups :
• Owner
• Group
• All other user
» Each file or directory has three basic permission types :
• Read
• Write
• Execute