Welcome to XXE Exposed! In this challenge, you'll explore XML External Entity (XXE) vulnerabilities in a corporate document parsing service. The application processes XML documents and extracts content, but contains a critical security flaw that allows attackers to read internal server files.

• Understand XML External Entity (XXE) attack vectors and techniques
• Learn about XML parsing vulnerabilities and external entity processing
• Practice file disclosure attacks through XML manipulation
• Develop skills in XML security analysis and exploitation

The challenge presents a corporate XML document parser that processes business documents for content extraction. You'll need to craft malicious XML payloads that exploit the external entity processing capabilities to read sensitive files from the server filesystem and retrieve the hidden flag.

XML External Entity (XXE) attacks exploit vulnerable XML parsers that process external entity references. When XML parsers resolve external entities without proper validation, attackers can read local files, perform SSRF attacks, or cause denial of service. This vulnerability is commonly found in web applications that process XML input from users.