Just a list of my favorite Firefox Add-ons.
FoxyProxy Standard
FoxyProxy is an advanced proxy management add-on for Firefox browser. It improves the built-in proxy capabilities of Firefox. Based on the URL patterns, it switches internet connection across one or more proxy servers. When proxy is in use, it also displays an animated icon. In case you want to see the proxies used by the tool, you can see the logs. Add it: https://addons.mozilla.org/en-US/firefox/addon/foxyproxy-standard/
Firebug
Firebug is a nice add-on that integrates a web development tool inside the browser. With this tool, you can edit and debug HTML, CSS and JavaScript live in any webpage to see the effect of changes. It helps in analyzing JS files to find XSS vulnerabilities. It.s an really helpful add-on in finding DOM based XSS for security testing professionals. Add it: https://addons.mozilla.org/en-US/firefox/addon/firebug/
Web Developer
Web Developer is another nice add-on that adds various web development tools in the browser. It helps in web application penetration testing. Add it: https://addons.mozilla.org/de/firefox/addon/web-developer/
User Agent Switcher
User Agent Switcher add-on; adds a one click user agent switch to the browser. It adds a menu and tool bar button in the browser. Whenever you want to switch the user agent, use the browser button. User Agent add on helps in spoofing the browser while performing some attacks. Add it: https://addons.mozilla.org/en-US/firefox/addon/user-agent-switcher/
Live HTTP Headers
Live HTTP Headers is a really helpful penetration testing add-on for Firefox. It displays live headers of each http request and response. You can also save header information by clicking on the button in the lower left corner. Add it: https://addons.mozilla.org/en-US/firefox/addon/live-http-headers/
Tamper Data
Tamper Data is similar to the Live HTTP Header add-on but, has header editing capabilities. With the tamper data add-on, you can view and modify HTTP/HTTPS headers and post parameters. It can be used in performing XSS and SQL Injection attacks by modifying header data. Add it: https://addons.mozilla.org/en-US/firefox/addon/tamper-data/
Hackbar
Hackbar is a simple penetration tool for Firefox. It helps in testing simple SQL injection and XSS holes. You cannot execute standard exploits but you can easily use it to test whether vulnerability exists or not. Add it: https://addons.mozilla.org/en-US/firefox/addon/hackbar/
Websecurify
Websecurify is a nice penetration testing tool that is also available as add-on for Firefox. WebSecurify can detect most common vulnerabilities in web applications. This tool can easily detect XSS, SQL injection and other web application vulnerability. Unlike other listed tools, it is a complete penetration testing tool in itself available as a browser add-on. It gives most of the features available in standalone tool. Add it: https://addons.mozilla.org/en-us/firefox/addon/websecurify/
Add N Edit Cookies
Add N Edit Cookies is a cookie editing add-on that allows you to add and edit cookies data in your browser. Add it: https://addons.mozilla.org/en-US/firefox/addon/add-n-edit-cookies-13793/
XSS Me
Cross Site Scripting is the most found web application vulnerability. For detecting XSS vulnerabilities in web applications, this add-on can be a useful tool. XSS-Me is used to find reflected XSS vulnerabilities from a browser. It scans all forms of the page, and then performs an attack on the selected pages with pre-defined XSS payloads. After the scan is complete, it lists all the pages that renders a payload on the page, and may be vulnerable to XSS attack. Now, you can manually test the web page to find whether the vulnerability exists or not. Add it: https://addons.mozilla.org/en-us/firefox/addon/xss-me/
SQL Inject Me
SQL Inject Me is another nice Firefox add-on used to find SQL injection vulnerabilities in web applications. This tool does not exploit the vulnerability but display that it exists. Add it: https://addons.mozilla.org/en-us/firefox/addon/sql-inject-me/
FlagFox
FlagFox is another interesting add-on. Once installed in the browser, it displays the country.s flag to tell the location of the web server. It also comes with other tools like whois, WOT scorecard and ping. Add it: https://addons.mozilla.org/en-us/firefox/addon/flagfox/
CryptoFox
CryptoFox is an encryption or decryption tool for Mozilla Firefox. It supports most of the available encryption algorithm. So, you can easily encrypt or decrypt data with supported encryption algorithm. Add it: https://addons.mozilla.org/en-US/firefox/addon/cryptofox/
Access Me
Access Me, is another add-on for security testing professionals. This add-on is developed by the company that works on XSS Me and SQL Inject Me. Access Me is the can Exploit-Me tool used for testing access vulnerabilities in web applications. This tool works by sending several versions of page requests. A request using the HTTP HEAD verb and a request using a made up SECCOM verb will be sent. A combination of session and HEAD/SECCOM will also be sent. Add it: https://addons.mozilla.org/en-US/firefox/addon/access-me/
SecurityFocus Vulnerabilities search plugin
SecurityFocus Vulnerabilities search plugin, is not a security tool but a search plugin that lets users search for vulnerabilities from the Security Focus database. Add it: https://addons.mozilla.org/en-us/firefox/addon/securityfocus-vulnerabilities-/
Packet Storm search plugin
This is another search plugin that lets users search for tools and exploits from packetstormsecurity.org. The website offers free up-to-date security tools, exploits and advisories. Add it: https://addons.mozilla.org/en-us/firefox/addon/packet-storm-search-plugin/
Offsec Exploit-db Search
It lets users search for vulnerabilities and exploits listed in exploit-db.com. This website is always up-to-date with latest exploits and vulnerability details. Add it: https://addons.mozilla.org/en-us/firefox/addon/offsec-exploit-db-search/
Snort IDS Rule Search
Snort IDS Rule Search is another search add-on for Firefox. It lets users search for Snort IDS rules on the snort.org website. Add it: https://addons.mozilla.org/en-US/firefox/addon/snort-ids-rule-search/
Imacros
Imacros allows you to automate almost all aspects of a website. Automate Firefox. Record and replay repetitious work. Add it: https://addons.mozilla.org/firefox/downloads/latest/3863/addon-3863-latest.xpi?src=dp-btn-primary
DownThemAll
The first and only download manager/accelerator built inside Firefox! Add it: https://addons.mozilla.org/firefox/downloads/latest/201/addon-201-latest.xpi?src=dp-btn-primary