"Just make everyone an admin"
A new program will not install for a user. The quick fix is to make her an administrator. It works. A week later she installs a game, and the game carries a virus.
The quick fix was the cause. Permissions need more thought.
Key words
| Word | What it means |
|---|---|
| Permission | a right to read, change or run a file or folder |
| Authorisation | deciding what a signed-in user may do |
| Least privilege | giving a user only the rights the job needs |
| Administrator | an account that can install software and change settings |
| Install | to put a program on a computer so it can be used |
| Impact | the effect something has |
| Usability | how easy a system is to use |
| Network | computers joined together so they can share data |
The cells students fill in are left blank in this preview.
By the end of this lesson
Note
I can say what permissions an install needs, apply least privilege and list the security impacts.
Starter
Have a go
Starter
3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.
Permissions for installing and running
To install a program, the installer must write files into protected folders. A normal user cannot do that. An administrator can.
After the install, the program needs permissions to run. It must be able to read its own files and write to the places it saves work. Folder and file access has to be set so the right users can run it, and no more.
Try to write to a protected folder
touch /usr/local/bin/mytoolA command for the lesson’s lab terminal. It is shown here and not run.
Look at who owns that folder
ls -ld /usr/local/binA command for the lesson’s lab terminal. It is shown here and not run.
Do the same with admin rights
sudo touch /usr/local/bin/mytool && ls -l /usr/local/bin/mytoolA command for the lesson’s lab terminal. It is shown here and not run.
Tidy up
sudo rm /usr/local/bin/mytoolA command for the lesson’s lab terminal. It is shown here and not run.