Change your browser

• The challenge expects our browser to be W3Challs_browser.

• We can begin by proxying the request through Burpsuite.

• Let's send this request to the Repeater.

User-Agent

User-Agent: Mozilla/5.0 (<system-information>) <platform> (<platform-details>) <extensions>

• The User-Agent holds information about the browser the client is using.

• We can replace the header to W3Challs_browser.

HTTP Request

GET / HTTP/1.1
Host: change-browser.hax.w3challs.com
User-Agent: W3Challs_browser
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate, br
DNT: 1
Connection: close
Upgrade-Insecure-Requests: 1
Sec-GPC: 1

• Next we have to send this modified request to the server.

Flag

W3C{now_that_we_have_the_right_browser_lets_get_the_party_started}