XXE Injection

XML External Entity (XXE) injection is a critical web security vulnerability that occurs within the Payload Execution phase through Injection Exploitation techniques. This vulnerability exploits XML parsers that process external entity references within XML documents without proper validation or restrictions. When threat actors successfully execute an XXE attack, they can access unauthorized files on the system, conduct server-side request forgery (SSRF), perform port scanning of internal systems, or execute remote code in certain scenarios. The attack leverages the XML 1.0 standard feature of external entities to manipulate applications into processing malicious declarations, potentially leading to sensitive data disclosure including system files, internal network resources, or credentials. XXE injection particularly targets applications that accept XML directly or accept content in XML format, such as SOAP services, REST APIs, or document processing functionalities, making it a significant threat vector in the payload execution stage of an attack chain.