In the “Network conditions” tab, uncheck the “ Select automatically” box next to “User agent”. You can also use the F12 key on your keyboard.įind “ Console” in the lower half of the window – if it is missing, then press the ESC button:Ĭlick the menu button to the right of the Console tab at the bottom of the developer toolbar and select “ Network conditions”.
Open them by clicking the Menu button and choosing More Tools → Developer Tools. The Chrome user agent switcher is part of the developer tools. Of course, there are many browser extensions for this, but you can spoof the User Agent even without them. We'll start with the simplest way to change User Agent – right in a web browser. Such vulnerabilities are usually not even accepted by Bounty programs (some large companies give a reward for vulnerabilities found, if you report them, this is called Bug Bounty). Web servers don’t really care what the exact user agent string is – they just check to see if it contains a specific word ( source).Īll XSS shown below are non-persistent, that is, they are only shown to the user who exploits them, and therefore are not dangerous. In this way, browser developers kept adding words to their user agents over time. WebKit was based on KHTML – when it was developed, they added the word WebKit and kept the original “KHTML, like Gecko” line for compatibility purposes. KHTML – originally developed for Konquerer on Linux’s KDE desktop – added the words “like Gecko” so they’d get the modern pages designed for Gecko, too. Other browsers that came later did the same thing.Įventually, some servers looked for the word Gecko – Firefox’s rendering engine – and served Gecko browsers different pages than older browsers. To fix this problem, Microsoft added the word Mozilla to their user agent and threw in additional information (the word “compatible” and a reference to IE.) Web servers were happy to see the word Mozilla and sent IE the modern web pages. However, IE didn’t receive web pages with frames, because web servers just sent those to Mozilla browsers. To other browsers, web servers sent the old pages without frames.Įventually, Microsoft’s Internet Explorer came along and it supported frames, too. Web servers checked to see that the user agent contained the word Mozilla and sent pages containing frames to Mozilla browsers. Mozilla was a more advanced browser than Mosaic – in particular, it supported frames. Later, Mozilla came along (later renamed Netscape), and its user agent was Mozilla/1.0.
Its user agent string was NCSA_Mosaic/2.0.
FIREFOX HACKING SITES HOW TO
This guide will show you how to change the User Agent and inject through the User Agent to pretend to be another device or perform attacks on the site. Spoofing User Agent to deceive the server How can the User Agent be used to attack websites? I know at least 3 options: To understand why, we’ll have to examine the history of user agents and browsers. The plot thickens: Chrome is pretending to be both Mozilla and Safari. The string is not very clear – it is clear that this is Chrome and that its version is 86. Or you can make it even easier – go to the page of one of the many services that show your User Agent: For example, in Google Chrome to do this, press F12, go to the Network tab and in the General window, find Request Headers: You can view the transmitted HTTP headers, including User Agent, in the Webmaster Developer Tools. User Agent is passed in the HTTP header when the browser makes a request to the web server. The User Agent is a string of text that identifies the browser and operating system for the web server.