Block add-ons installation from file
I have been researching a way to block add-ons installations in Firefox. I have read tons of articles but I'm still not able to block add-ons installation from a file.
One thing that almost all articles I read had in common was the use of this setting:
xpinstall.enabled = false
I have this setting set to false. The icon to search for add-ons online is gone! But I'm still able to download an add-on manually from the web and use the "Install add-on from file..." option.
How can I block this? What am I missing?
I'm sending screenshots from my computer. But the last one I extracted from a tutorial showing a message that the add-ons installation was blocked by the administrator. But I never was able to reproduce this behavior.
Some articles I read: https://www.itsupportguides.com/knowledge-base/windows-7/firefox-10-how-to-disable-addon-plugin-installation// https://www.ghacks.net/2013/02/20/how-to-block-new-add-on-or-plugin-installations-in-firefox/
Firefox versions I tested: 51.0.1 (64-bit) for Windows 57.0.2 (64-bit) for Windows
All Replies (6)
This is not a Firefox Issue. You are asking Developer Questions for Developing a blocking system. If you are not just do not install any Addons or Extensions. https://www.mozilla.org/en-US/developer/
Pkshadow said
This is not a Firefox Issue. You are asking Developer Questions for Developing a blocking system. If you are not just do not install any Addons or Extensions. https://www.mozilla.org/en-US/developer/
This answer doesn't answer my question. I need to know if there is a configuration to block the installation of extensions from files (.xpi files) in Firefox. If there is how do I do it?
I searched and tried a lot of tutorials in the internet but none of them worked for this specific condition. I don't know if it is a bug or if I'm missing something.
I need to block these installations in order to allow the use of Firefox in my company.
Thanks.
Hi,
You will undoubtedly already have done this, but just in case :
In Options => Privacy & Security => under 'Permissions', did you check 'Warn you when websites try to install add-ons' ?
Are you using mozilla.cfg to lock xpinstall.enabled = false?
//
lockPref("xpinstall.enabled", false);
lockPref("extensions.enabledScopes", 0);
See Configuration:
See also:
Modified by cor-el
First of all, thank you guys for your answers.
Happy112, The 'Warn you when websites try to install add-ons' is already activated.
cor-el, Yes, I'm using the mozilla.cfg to lock xpinstall.enabled and extensions.enabledScopes to false and 0 respectively.
But I'm still able to install a xpi extension from a file in my file system.
The difference from your articles is that I'm not using an ESR release. I'm using a portable version from Firefox (v 57) for testing these settings. Could this be the problem?
I'm sending some new images of my experiences.
Yes, that could be the issue. Firefox Portable isn't from Mozilla, it is a 3rd party build that is built from the Firefox source code.
Best to test using an official Release to rule out the modifications that PortableApps does to Firefox to "package" it as a "portable app" isn't affecting how it works in an "install from local disk" operation.