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Was there any Webkit based Firefox or is it UA spoofing?

yannick_duchene replied
yannick_duchene

Hi all the people,

I was just surprised to see this in an Apache HTTP log: "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Firefox/58.0.1"

This bugs me. My first guess would be that a Webkit based Firefox could not be qualified as really Firefox. Although that, I could imagine a Firefox for iOS or MacOS based on Webkit, may be, but it says it is on Windows, which makes less sense.

I suspect this is a user agent string spoofing, but I just need to be sure (I try to get ride of far too invasive bots, while I’m afraid to disrupt browsing from legitimate web users).

With thanks and my apologizes for such a question which may looks obvious or strange to people who know for sure.

Hi all the people, I was just surprised to see this in an Apache HTTP log: "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Firefox/58.0.1" This bugs me. My first guess would be that a Webkit based Firefox could not be qualified as really Firefox. Although that, I could imagine a Firefox for iOS or MacOS based on Webkit, may be, but it says it is on Windows, which makes less sense. I suspect this is a user agent string spoofing, but I just need to be sure (I try to get ride of far too invasive bots, while I’m afraid to disrupt browsing from legitimate web users). With thanks and my apologizes for such a question which may looks obvious or strange to people who know for sure.

すべての返信 (11)

It may be a bot, UA switcher, some old fork, or perhaps someone has found it in random reddit thread and overridden default UA years ago.

選ばれた解決策

WebKit–based Firefox iOS browsers do not use "Firefox" as the product bit, for pretty much this exact reason.

This is not, and never has been a Gecko–based Firefox UA. (See https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers/User-Agent/Firefox for the canonical source.)

This looks like some "randomizer" extension trying to resist fingerprinting by scrambling the bits, but mostly looks like a chromium–based UA, like a Brave or Opera would use, with something messing with the product trailers.

yannick_duchene said

This bugs me. My first guess would be that a Webkit based Firefox could not be qualified as really Firefox. Although that, I could imagine a Firefox for iOS or MacOS based on Webkit, may be,

Firefox on iOS/iPadOS is a shell for webkit due to Apple's restrictions on what browser engine can be used though in some certain markets now due to a court ruling Mozilla could technically make Firefox on Gecko on iOS/iPadOS for those markets.

The desktop Firefox on macOS uses Gecko like the Linux and Windows versions does.

The problem with trying to randomize a UA is that you are then making the UA more unique and the user easier to track. Mozilla has been making the Firefox UA more generic over the years as to why the build date been removed and the minor update version has not been shown since Fx 16.0.2? if I recall and Firefox on 32-bit Windows and Linux shows as 64-bit.

この投稿は James により に変更されました

So reading all your three answers, I learned some browsers generate strange user agent strings, on purpose. Of course, I was not to test only it, also the behavior, but I was thinking the user agent notice could be a good hint to start with. It may not even be …

Will wait a bit before marking the topic as solved, in case some other people would like to say more.

Have a nice day

この投稿は yannick_duchene により に変更されました

To give you the idea: https://discourse.mozilla.org/t/extraneous-product-version-combinations-in-user-agent-ex-herring-94-1-8750-51-openwave-96-4-6033-34/107587/5

It has e.g. AVG Anti Track and CCleaner’s Kamo mentioned. Browsers usually know better than do this as it actually makes the user stand out way more, than the opposite (blending with the millions of users on the same release) — so it's usually the various addons and protection software manufacturers that think to know better. 🤷

If your Firefox UserAgent has been modified by an extension or such then you may be able to reset it by method in https://support.mozilla.org/en-US/kb/how-reset-default-user-agent-firefox

Try and post in most current topic regards web access on Win 7. From about:support what is being reported by the default user agent (built in) on my machine.

Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:109.0) Gecko/20100101 Firefox/115.0

Now I have the same problem on Home Depot, Lowes, Tractor Supply. One reply I read here mentioned a reply from Akamai is that your browser is older than 3 years.

Well if Akamai filter is goin by RV 109.0 then its 3 years old this Feburary, and if they are going by Firefox 115.0 it is close to 3 years.

If Firefox would amend the default numbers to at least Firefox 115.30 and rv from 109.0 to 115.30 in the next update it would make the browser more current and pass the Akamai filter test. Some Firefox developers could at least test this suggestion.

Wrong thread ^^ but feel free to check some of the relevant threads what happens with spoofed version numbers for those bot blocks. (The builds have distinct connection signatures, so it's trivial to tell them apart if the user agent is fake.)

この投稿は Agent virtuel により に変更されました

An experience performed with the help of Responsive Design Mode https://firefox-source-docs.mozilla.org/devtools-user/responsive_design_mode

User Agent String on the right

Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:109.0) Gecko/20100101 Firefox/115.0

この投稿は Agent virtuel により に変更されました

jbr a écrit

Wrong thread ^^ but feel free to check some of the relevant threads what happens with spoofed version numbers for those bot blocks. (The builds have distinct connection signatures, so it's trivial to tell them apart if the user agent is fake.)

How do I have to understand “have distinct connection signatures”?

Ok, will search the forum for “spoofed version numbers”.

-)
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