Pdfy Htb Writeup Upd [portable] ✦ ❲PREMIUM❳

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

john --single /tmp/shadow

Hack The Box (HTB) is a popular online platform that provides a challenging and interactive environment for cybersecurity enthusiasts to test their skills. One of the recent challenges on HTB is PDFY, a medium-level difficulty box that requires a combination of web exploitation, file analysis, and system compromise. In this writeup, we will walk through the step-by-step process of solving the PDFY challenge, highlighting the key techniques and tools used.

Server-Side Request Forgery (SSRF) & Local File Inclusion (LFI) Target Binary Component: wkhtmltopdf 1. Initial Reconnaissance & Enumeration pdfy htb writeup upd

ngrok http 8080

To bypass this input filter, you can host a rogue web script on your own infrastructure (VPS or a localized tunneling solution like Serveo). When the HTB server requests your server's public URL, your script will return an HTTP redirection code ( 302 Found ) pointing directly to the internal files. Because the backend engine handles redirections programmatically, it follows the redirected path internally, bypassing the frontend input validation. Phase 3: Step-by-Step Exploitation Step 1: Prepare the Redirection Exploit File

Inputting a direct internal scheme or local IP loopback address (e.g., http://127.0.0.1 or file:///etc/passwd ) results in an error message. The application implements a basic script validation layer to prevent users from requesting internal resources directly. 3. Identifying the Rendering Engine Always validate and sanitize user-provided URLs

gobuster dir -u http://10.10.10.XXX -w /usr/share/wordlists/dirb/common.txt

"converter": "command": "/usr/bin/python -c 'import os; os.system(\"chmod +s /bin/bash\")'"

The server will accept your legitimate http:// URL, process the request, hit your endpoint, receive the 302 Redirect instructions to look at file:///etc/passwd , and capture the contents of the target machine's system files directly into the generated PDF file. Step 4: Exfiltrate the Flag One of the recent challenges on HTB is

Save the following code as index.php on your local attacker machine: Use code with caution. Copied to clipboard

PDFy HTB Writeup: Exploiting SSRF in wkhtmltopdf to Read Arbitrary Files

The scan reveals the following open ports:

Create symlink to root’s SSH key? Not possible. Instead:

su newuser