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Spring4Shell-POC (CVE-2022-22965)

Spring4Shell (CVE-2022-22965) Proof Of Concept/Information + A vulnerable Tomcat server with a vulnerable spring4shell application.

Early this morning, multiple sources has informed of a possible RCE exploit in the popular java framework spring.

The naming of this flaw is based on the similarities to the infamous Log4j LOG4Shell.

Details about this vulnerability

• https://websecured.io/blog/624411cf775ad17d72274d16/spring4shell-poc
• https://www.springcloud.io/post/2022-03/spring-0day-vulnerability
• https://spring.io/blog/2022/03/31/spring-framework-rce-early-announcement

POC Usage

The usage is simple! You can either run the docker image, or just run the python script!

Please see vulnerable-tomcat for inscructions on setting up your own spring4shell vulnerable application here!

Requirements

• Python3 or Docker

Python

pip install -r requirements.txt
poc.py --help

Docker

## Dockerhub
docker pull bobtheshoplifter/spring4shell-poc:latest
docker run bobtheshoplifter/spring4shell-poc:latest --url https://example.io/
## Github docker repository
docker pull ghcr.io/bobtheshoplifter/spring4shell-poc:main
docker run ghcr.io/bobtheshoplifter/spring4shell-poc:main --url https://example.io/

Vulnerable Tomcat server

I have now made a docker image for this, which includes a vulnerable spring + tomcat application.

The application should be enough to test this vulnerability.

Please see (vulnerable-tomcat/README.md)

Mitigations

!!(The following mitigations are only theoretical as nothing has been confirmed)!!

JDK Version under 9

Cyberkendra informed that JDK versions lower than JDK 9

You can easily check this by running

java -version

That will display something similar to this

openjdk version "17.0.2" 2022-01-18
OpenJDK Runtime Environment (build 17.0.2+8-Ubuntu-120.04)
OpenJDK 64-Bit Server VM (build 17.0.2+8-Ubuntu-120.04, mixed mode, sharing)

If your JDK version is under 8, you might be safe, but nothing is confirmed yet

The following article will be updated

Check if you are using the spring framework

Do a global search after spring-beans*.jar and spring*.jar

find . -name spring-beans*.jar

POC, translated fron this repository: https://github.com/craig/SpringCore0day/blob/main/exp.py