Update – Based on feedback, I failed to distinguish that I’m referring to normal users running as admin. Sysadmins and domain admins definitely shouldn’t be running with their admin privileges except for when they need them. As you can read in the comments, that’s a huge risk.
When I was reviewing Mike’s FireStarter on yanking admin rights from users, it got me thinking on whether admin rights really matter at all.
Yes, I realize this is a staple of security dogma, but I think the value of admin rights is completely overblown due to two reasons:
- There are plenty of bad things an attacker can do in userland without needing admin rights. You can still install malware and access everything the user can.
- Lack of admin privileges is little more than a speed bump (if even that) for many kinds of memory corruption attacks. Certain buffer overflows and other attacks that directly manipulate memory can get around rights restrictions and run as root, admin, or worse. For example, if you exploit a kernel flaw with a buffer overflow (including flaws in device drivers) you are running in Ring 0 and fully trusted, no matter what privilege level the user was running as. If you read through the vulnerability updates on various platforms (Mac, PC, whatever), there are always a bunch of attacks that still work without admin rights.
I’m also completely ignoring privilege escalation attacks, but we all know they tend to get patched at a slower pace than remote exploitation vulnerabilities.
This isn’t to say that removal of admin rights is completely useless – it’s very useful to keep users from mucking up your desktop images – but from a defensive standpoint, I don’t think restricting user rights is nearly as effective as is often claimed.
My advice? Do not rely on standard user mode as a security defense. It’s useful for locking down users, but has only limited effectiveness for stopping attacks. When you evaluate pulling admin rights, don’t think it will suddenly eliminate the need for other standard endpoint security controls.