The flag will typically look like this: BKPF{web_exploitation_master_2023_xyz} ⚠️ Note on File Extraction If you are having trouble opening the file: Ensure you have ( part1 through part4 ). Place them in the same folder.
Once you have bypassed the local checks discovered in the part4 files: Intercept the request using .
Look for the secret_key in the configuration files found in the archive. BKPF23WEB18.part4.rar
Many of these challenges require reaching an internal "Metadata" service or a local file. Check for functions like fetch() or os.path.join() . ?file=../../../../flag.txt Step 3: Extracting the Flag
Multi-part RAR files usually contain the source code of the web application. Part 4 typically includes: Look for the secret_key in the configuration files
docker-compose.yml or .env files that reveal internal networking. 2. The Vulnerability: Parameter Pollution / Logic Bug
You might see a check like if (req.body.user === 'admin') , which can be bypassed if user is passed as an array ['guest', 'admin'] . 🛠️ Exploitation Steps Step 1: Analyze the Authentication BKPF23WEB18.part4.rar
If the key is "hardcoded" or "leaked," you can forge an admin session. Step 2: Path Traversal or SSRF