Looking Glass Hack The Box Firewalker CTF 🔎 💉
https://ctf.hackthebox.com/ctf/240
Point: 325
Category
Web-Exploitation
Question
We’ve built the most secure networking tool in the market, come and check it out
Solution
This challenge is a remote code execution vulnerability challenge. You are given a web page to test out web-based networking tools namely ping and traceroute. The web page is quickly popped in Owasp ZAP to recon the requests and responses to and from the server. 
A breakpoint is set to examine the request further. 
From the request, we can see that a ping request is sent to the server in the following format. test=ping&ip_address=188.166.174.107&submit=Test
A test injection command is crafted in the command as below to see if the request would be vulnerable to remote code execution on the server.
test=ping&ip_address=188.166.174.107;id&submit=Test
Indeed, the web application is vulnerable to an RCE from the response. 
Another test command is crafted to further enumerate the context of the environment we’re in as below. test=ping&ip_address=188.166.174.107;pwd&submit=Test 
The command again shows that we are in the www directory of the server. 
We can see from here that there is a flag file one level up from the www directory of the server. 
The final command is crafted further to read the contents of the flag file. test=ping&ip_address=188.166.174.107;cd ..;cat flag_Hy10K&submit=Test 
The output of the contents is then shown in the output pane of the looking glass web application. 
Improvement
None
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