Checking whether a web server is an open proxy
HTTP proxies are used to make requests through their addresses, therefore hiding our real IP address from the target. Detecting them is important if you are a system administrator who needs to keep the network secure or as an attacker looking to spoof your real origin. Misconfigured web servers are more common than we think, and they could be abused by attackers if left exposed.
This recipe shows you how to use Nmap to detect an open HTTP proxy.
How to do it...
Open your terminal and enter the following command:
$ nmap --script http-open-proxy -p8080 <target>
The results include the HTTP methods that were successfully tested and if the proxy is indeed exposed:
  PORT STATE SERVICE
  8080/tcp open http-proxy
  | proxy-open-http: Potentially OPEN proxy.
  |_ Methods successfully tested: GET HEAD CONNECT
How it works...
We use the Nmap options --script http-open-proxy -p8080
to launch the NSE script http-open-proxy
if a web server is...