"The Threat Classification is an effort to classify the weaknesses, and attacks that can lead to the compromise of a website, its data, or its users."
The WASC Threat Classification is a cooperative effort to clarify and organize the threats to the security of a web site. The members of the Web Application Security Consortium have created this project to develop and promote industry standard terminology for describing these issues. Application developers, security professionals, software vendors, and compliance auditors will have the ability to access a consistent language and definitions for web security related issues.
The WASC Threat Classification Online