The FREE Cybersecurity Glossary by Thor Pedersen!

X.500: X.500 is a standard for directory services used to store and organize information about users, resources, and services on a network. Examples of X.500-based directories include Active Directory and LDAP.

X.509 V3: A standard for public key certificates, which are used to verify the identity of a user or device in a network. It is used in secure communication protocols such as SSL/TLS, which require the use of certificates for authentication and encryption. Examples of X.509 V3 certificates include SSL/TLS certificates, digital signatures, and client authentication certificates.

Xmas Attack/Scan: A network scanning technique that manipulates the TCP header flags, sending packets with the FIN, URG, and PSH flags set—resembling a lit-up Christmas tree. It is designed to probe for responses that can reveal information about active services on network devices, potentially identifying vulnerable targets for further exploits.

XML Injection: An attack where malicious XML code is inserted into a system, exploiting insecure processing of XML input by an application. This can affect the logic of XML parsers, leading to unauthorized access, data exposure, or service disruption. It's distinct from other injection attacks by specifically targeting XML parser vulnerabilities.

XOR: A logical operation that outputs true only when one of the inputs is true. It is commonly used in computer science and cryptography to perform logical operations and encrypt data. Examples include binary XOR, bitwise XOR, and Boolean XOR.

Zachman framework: A system for categorizing and organizing the components of an enterprise architecture. It is used by organizations to help plan, design, and implement complex information systems and to ensure alignment with business goals and strategies. Examples of Zachman framework components include data, function, network, people, and time.