Angular XML External Entities (XXE) Guide: Examples and Prevention

An XML External Entity (XXE) attack exploits vulnerabilities in applications that process XML documents by using malicious XML constructs to compromise data security or cause a denial of service. These attacks take advantage of XML external entities, which can reference data from external sources, including internal networks or files, leading to unauthorized data access or application malfunctions. Prevention involves ensuring that applications do not process untrusted data in unsafe ways, and using secure XML parsers like xml2js or sax-js, which default to ignoring or safely handling custom entities. The discussion includes examples of how XXE attacks can retrieve network information, steal files, and execute denial-of-service attacks, emphasizing the importance of using the right parsers and keeping dependencies updated to protect Angular applications. The post, authored by Eric Goebelbecker, also suggests utilizing tools like StackHawk to enhance application security further.