What is XML External Entity?
XML external entity or XXE is a web vulnerability that enables threat actors to mess with an application’s XML data processing. XML stands for “Extensible Markup Language,” a plaintext file format for storing and transporting data over the Internet.
An e-commerce platform, for example, may use XML to define product listings and specify each product’s description, price, and shipping details. This data can be sourced from an external file, and the weakness lies there.
XML external entity attacks, also known as “XML external entity injection,” take advantage of an XML feature that allows an application to read external files. Attackers may use it to read and retrieve internal files, launch denial-of-service (DoS) attacks, perform port scanning, and other dangerous exploits.