Finding bugs in dynamic web applications

TitleFinding bugs in dynamic web applications
Publication TypeConference Paper
Year of Publication2008
AuthorsArtzi, S., A. Kiezun, J. Dolby, F. Tip, D. Dig, A. Paradkar, and M. D. Ernst
Conference NameProceedings of the 2008 international symposium on Software testing and analysis - ISSTA '08
Date Published07/2008
PublisherACM Press
Conference LocationSeattle, WA, USA
ISBN Number9781605580500

Web script crashes and malformed dynamically-generated Web pages are common errors, and they seriously impact usability of Web applications. Current tools for Web-page validation cannot handle the dynamically-generated pages that are ubiquitous on today's Internet. In this work, we apply a dynamic test generation technique, based on combined concrete and symbolic execution, to the domain of dynamic Web applications. The technique generates tests automatically, uses the tests to detect failures, and minimizes the conditions on the inputs exposing each failure, so that the resulting bug reports are small and useful in finding and fixing the underlying faults. Our tool Apollo implements the technique for PHP. Apollo generates test inputs for the Web application, monitors the application for crashes, and validates that the output conforms to the HTML specification. This paper presents Apollo's algorithms and implementation, and an experimental evaluation that revealed 214 faults in 4 PHP Web applications.