From 29th March to 3rd April 2009 the Dagstuhl Seminar 09141 Web Application
Security was held in Schloss Dagstuhl -- Leibniz Center for Informatics. During the
seminar, several participants presented their current research, and ongoing work
and open problems were discussed. Abstracts of the presentations given during the
seminar are put together in this paper. Links to full papers (if available) are
provided in the corresponding seminar summary document.