I'll ask my engineers to post the one he wrote. He did put more details into the article, so go check that. Here is a repo with a POC though: https://github.com/TheGejr/SpringShell
Yeah it doesn't work with a default Spring MVC project from start.spring.io on Jdk 18. It's hardly a proof of concept without any configuration details of the spring project. Security researchers need to do better than this.