The Register article has a bit more information. This isn't really a vulnerability. It's definitely not "remote code execution". It works like this:
- Microsoft provides a tool called AppLocker that can be used to limit the programs that can be run on a system.
- The AppLocker tool is not intended as a tight "security boundary". Instead, it is a way to implement company policies like "no playing games at work", or to help with software licensing, i.e. "the company system image has a copy of Photoshop, but you aren't in the Design department, so you aren't licensed to run it", and perhaps to reduce attack surface area.
- The Microsoft-provided sample AppLocker configuration (intended to show the syntax for AppLocker rules) happens to have a sample rule that whitelists all programs under C:\windows. This is not a "recommended" rule -- it's a "sample" rule.
- If you leave this rule in, there are a large number of ways to escape the sandbox.
- A researcher found another one. Yay, I guess?
The new one is interesting because I wouldn't have considered regsvr32 to be a command that allows for running of arbitrary other commands. On the other hand, it shouldn't belong in a production whitelist in the first place, so being able to use it to escape the sandbox isn't particularly interesting.
If you didn't have to work so hard, you'd have more time to be depressed.