To give you an example of where this could be bad as a home user:
Your web browser runs as your user account. If there's some way for this to run code as your user account (e.g., browser bug), this local privilege escalation could then be called from your web browser.
So... combination of bugs = attacker gets root access from your browser.
- the browser gets exploited to run code within the user context it runs in
- the command run in that context elevates it to root.
So, the local privilege vulnerability isn't directly a critically urgent problem
by itself for most home users but when chained together with another bug such as above, it can be bad. So patch! You're less at risk than people directly exposing their machine to untrusted users, but it's only a matter of time!
But its super critical if you have untrusted users already logging into the box, e.g., my situation where we have 100 staff logging into the box that runs the company accounts
😀
Or if you're an internet provider for example, or way worse, running say, GitHub, where your users can literally tell GitHub to run code automatically for them.