Approx a year back, Mozilla added a new feature “Captive Portal” support to Firefox browser in an attempt to enhance usability when connecting to free Wi-Fi portals.
Captive Portal feature covers the detection and implementation of handles for captive portals inside Firefox browser. Firefox is expected to handle the handling of a captive portal page upon detection of such. Certain business logic related to the detection and management of a captive portal is expected to be in place and documented in the Specs section.
This feature is really annoying when it comes to using Burp Suite as a proxy for Firefox. Because if you are a pentester, you are probably used using Firefox for traffic interception through Burp Intercept but along with normal requests, you may seen a lot of GET requests of /success.txt as shown below:
Seeing all those requests in Burp, much less thinking about all the noise they generate otherwise, is annoying. Because you probably won’t ever need to use a Captive Portal on your pentesting machine.
Open your Mozilla Firefox browser, and type “about:config” and click on “I accept the risk!” as shown in below screen.
Search “captive-portal” in the search bar and you’ll see some entries related to captive portal named as “network.captive-portal-service.enabled” whose default value is false and you just need to double click on the following entry to set it true.