Firefox makes HTTP requests when browsing Applications Preferences




4 years ago
a year ago


(Reporter: jenda.uoe63u, Unassigned, NeedInfo)




Firefox Tracking Flags

(Not tracked)




4 years ago
Firefox automatically downloads favicons for some predefined web services when browsing Preferences. Additionally, these requests leak cookies. This happens even with Private browsing windows and I haven't found a way to stop it.

How to reproduce:
 1) Open Edit -> Preferences
 2) Click Applications
 3) Click "irc", "ircs" or "mailto"
 4) Firefox makes requests to,, and happily sending cookies too.
 5) If Applications tab is left selected, Firefox does this again immediately after cleaning cache, restart and opening Preferences

Setting gecko.handlerService.schemes.irc.0.uriTemplate to localhost does not help and there are no other occurrences of keywords like "mibbit" in about:config.

Reference: bug #480826
OS: Linux → All
Hardware: x86_64 → All
Summary: Firefox makes HTTP requests when browsing Preferences → Firefox makes HTTP requests when browsing Applications Preferences
Version: 29 Branch → Trunk

Comment 1

3 years ago
Yeah, cookies should not be sent as the user is not voluntarily visiting the site.
The logic for fetching the icons probably is to get an up to date icon as the site itself is using so that the user recognizes it in the list.
Keywords: privacy
What's the current status of this, please? Is this confirmed and still existing issue?
Flags: needinfo?(acelists)
As it is Mibbit and e-mail services, I assume it happens in the Applications panel when it tries to fetch the favicons of the predefined providers. So the lists of servers will depend on the Firefox localization (or about:config preferences).
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