Pdfy Htb Writeup: Upd

Always validate and sanitize user-provided URLs. Blacklisting "localhost" or "file://" is rarely sufficient, as redirects can often bypass these filters.

The wkhtmltopdf engine follows the redirect and reads the local file. The content of /etc/passwd is rendered into the PDF. pdfy htb writeup upd

If you are running this locally, you must expose your server to the internet so the HTB challenge instance can reach it. Using a Reverse Proxy or tools like Serveo is recommended over ngrok for this specific challenge to avoid browser warning screens that might break the automated PDF rendering. Always validate and sanitize user-provided URLs

You need a way to serve a 302 Redirect . You can use a simple PHP script or a Python server to achieve this. Use code with caution. Step B: Expose Your Server The content of /etc/passwd is rendered into the PDF