Are there any open source solutions for testing web security vulnerabilities? I am not looking to make my web application bullet proof since it'll be used internally at our organization. But I'd like to test it for the bare essentials from a web security perspective.
Zed Attack Proxy from OWASP - https://www.owasp.org/index.php/OWASP_Zed_Attack_Proxy_Project
And generally I would advise browsing the site to learn more about security
Metasploit community edition is free - http://www.metasploit.com/about/choose-right-edition/