Just ran across these –

https://addons.mozilla.org/en-US/firefox/collection/redspin-web

Specifically these are pretty handy.

There are some tools that can test for Cross Site scripting and SQL injection.

https://addons.mozilla.org/en-US/firefox/addon/6727?collection_uuid=0e892c37
SQL Injection is an Upgrade from the old form free, it is a component to transform checkboxes, radio buttons, select elements to a input text and enable disabled elements from all forms in a page. It makes easier to test and identify SQL injection vulnerabilities in web pages.

https://addons.mozilla.org/en-US/firefox/addon/7597?collection_uuid=0e892c37
SQL Injection vulnerabilites can cause a lot of damage to a web application. A malicious user can possibly view records, delete records, drop tables or gain access to your server. SQL Inject-Me is Firefox Extension used to test for SQL Injection vulnerabilities.

https://addons.mozilla.org/en-US/firefox/addon/7598?collection_uuid=0e892c37
 Cross-Site Scripting (XSS) is a common flaw found in todays web applications. XSS flaws can cause serious damage to a web application. Detecting XSS vulnerabilities early in the development process will help protect a web application from unnecessary flaws. XSS-Me is the Exploit-Me tool used to test for reflected XSS vulnerabilities.