Please note that the content of this book primarily consists of articles
available from Wikipedia or other free sources online. HTTP header
injection is a general class of web application security vulnerability
which occurs when Hypertext Transfer Protocol (HTTP) headers are
dynamically generated based on user input. Header injection in HTTP
responses can allow for HTTP response splitting and cross-site scripting
(XSS) attacks. HTTP header injection is a relatively new area for
web-based attacks, and has primarily been pioneered by Amit Klein in his
work on request/response smuggling/splitting.