I'm on to an R & D task for testing the security vulnerabilities that can happen in a web application. I want to use an open source tool.
There are many type of vulnerabilities like Cross Site Scripting, Denial of Service, File Access, Format Validation, Mass Assignment, SQL Injection, Session Setting, etc. So, I would like to have a best fit cross platform tool to do penetration testing in a best possible way.
I've gone through Security testing of web application and Open source web security testing tools, and I found it useful. But, as it was posted a year ago, I would like to have an updated answer.