Get the Whitepaper called Security of the Web. This papers discusses how vulnerabilities have evolved over the years and how web applications have become a primary vector of attack. Written in German.
You can download it from the following link: https://packetstormsecurity.com/files/download/79196/security-web.pdf
Source: https://packetstormsecurity.com/files/79196/Whitepaper-Called-Security-Of-The-Web.html