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Spring4Shell PoC Application

This is a dockerized application that is vulnerable to the Spring4Shell vulnerability (CVE-2022-22965). Full Java source for the war is provided and modifiable, the war will get re-built whenever the docker image is built. The built WAR will then be loaded by Tomcat. There is nothing special about this application, it's a simple hello world that's based off Spring tutorials.

Details: https://www.lunasec.io/docs/blog/spring-rce-vulnerabilities

Requirements

1. Docker
2. Python3 + requests library

Instructions

1. Clone the repository
2. Build and run the container: docker build . -t spring4shell && docker run -p 8080:8080 spring4shell
3. App should now be available at http://localhost:8080/helloworld/greeting

4. Run the exploit.py script: python exploit.py --url "http://localhost:8080/helloworld/greeting"

5. Visit the created webshell! Modify the cmd GET parameter for your commands. (http://localhost:8080/shell.jsp by default)

Notes

Fixed! As of this writing, the container (possibly just Tomcat) must be restarted between exploitations. I'm actively trying to resolve this.

Re-running the exploit will create an extra artifact file of {old_filename}_.jsp.

PRs/DMs @Rezn0k are welcome for improvements!

Credits

• @esheavyind for help on building a PoC. Check out their writeup at: https://gist.github.com/esell/c9731a7e2c5404af7716a6810dc33e1a
• @LunaSecIO for improving the documentation and exploit
• @rwincey for making the exploit replayable without requiring a Tomcat restart