• 3000003: Firefox – additional security, telemetry and privacy tweaks

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    AKB3000003: Firefox – additional security, telemetry and privacy tweaks

    By @Microfix

    Published 15 Feb 2017 rev 1.1

    These tweaks are for both Windows and Linux firefox browsers:

    Edit by NightOwl:

    Forgot the 1st rule in computing..backup, backup before making changes.

    Thanks PKCano, Can you put your backup comment at the start of the tweak tutorial?

    The Firefox profile is in C:\Users\”UserID”\AppData\Roaming\Mozilla\Firefox\Profiles\”an arbitrary numeric string”\ – it contains bookmarks, settings, add-ons, extensions, features, etc.

    You need to backup your FireFox pre-changes Profile before making changes, in case something unexpected goes wrong when making changes, so you can restore your pre-changes Profile if something has gone wrong!

    Open up firefox and in the address bar type: about:config
    A popup will appear ‘Here be Dragons’ accept the risks and proceed.
    Then in the filter search either copy and paste the string or edit value.
    To change string values, double click the string to change.

    Security: Additional browser security
    For the LOGJAM vulnerability follow the steps below:
    1) Type: security.ssl3.dhe_rsa_aes_128_sha set to FALSE
    2) Type security.ssl3.dhe_rsa_aes_256_sha set to FALSE

    Disable SSL 3.0 to be immune from the POODLE attack:
    1) Type: security.tls.version.min set to 1 to enforce TLS.
    2) Type: security.tls.version.max set to 3, which enables TLS 1.1 and 1.2 (default in FF v50+)

    Telemetry blocking:
    1) Type: toolkit.telemetry.unified set to FALSE
    2) Type: toolkit.telemetry.archive.enabled set to FALSE
    3) Type: toolkit.telemetry.enabled set to FALSE
    4) Type: datareporting.policy.dataSubmissionEnabled set to FALSE
    5) Type: datareporting.policy.dataSubmissionEnabled.v2 set to FALSE (Pre v50 firefox)
    6) Type: datareporting.healthreport.uploadEnabled set to FALSE

    Additional Privacy Tweaks:
    1) Type: browser.privatebrowsing.autostart set to TRUE (if you prefer private browsing all the time)
    2) Type: dom.event.clipboardevents.enabled set to FALSE (hides Copy & Paste from Website tracking)
    3) Type: dom.storage.enabled set to FALSE (prevent DOM Storage tracking by websites) Refer to #95310 for caution
    4) Type: geo.enabled set to FALSE (geolocation prevention via websites, explicit or not)
    5) Type: geo.wifi.uri set to (Loopback related to geolocation and not to google host)
    6) Type: privacy.trackingprotection.enabled set to TRUE (enables a blocklist via disconnect on cross site tracking)

    Disclaimer: I am not reponsible for borking your firefox, try these at your own risk.
    I can assure you that they all work on our live and VM systems.

    6 users thanked author for this post.
    Viewing 20 reply threads
    • #94469

      Is there a way to backup/restore for the current settings before making adjustments, and is there a “factory reset” option, to return to default settings, should things go awry?

      • #94472

        Kirsty, I don’t know if there is a formal way to backup the config. but what you can certainly do is go into the Mozilla/Firefox Profiles folder, make a copy of your profile and then, if things go off, you can simple use this “copy” to go back to your previous state.

        9 users thanked author for this post.
      • #94535

        The Firefox profile is in C:\Users\”UserID”\AppData\Roaming\Mozilla\Firefox\Profiles\”an arbitrary numeric string”\ – it contains bookmarks, settings, add-ons, extensions, features, etc.
        This is one of the MANY reasons for backing up the AppData folder (hidden by default, unfortunately). When people do backups, they often just do Documents, Pictures, Music (the things that are not hidden). But the AppData folder is SO important as well.
        When PCs are taken to shops to retrieve data from failing HDDs or non-bootable computers, this data is often not saved.

        8 users thanked author for this post.
        • #94543

          Thanks PKCano,
          Can you put your backup comment at the start of the tweak tutorial?
          Forgot the 1st rule in computing..backup, backup before making changes.(been a long day..)

          Keep IT Lean, Clean and Mean!
    • #94470

      hello n.n

      i have a question… what about plug ins like Privacy Settings from firefox addons, it’s useful?
      thanks n.n

      • #94523

        It’s a matter of personal preference really, not fond of extensions in Firefox.
        If any of the tweaks are duplicated, Privacy Settings will just enforce it again so no harm done there.
        The top two security tweaks are the most important LOGJAM & POODLE even if they are set correctly without changing them, it’s better to check anyway.

        Keep IT Lean, Clean and Mean!
        3 users thanked author for this post.
      • #95659

        this plugin sets network.http.sendSecureXSiteReferrer to false what breaks aliexpress login
        removing this plugin dont turn settings back, they must done by hand

    • #94480

      ? says:
      Thanks for the heads up everyone appreciates all the extra security we can get these days…
      I’m running persistent live cd usb’s so i’m not too worried about any more borking than I already do for myself. I ran all the telemetry blocking after you let us know about it the other day and no problems, so far.
      Check with our security loving German compatriot Martin Brinkmann’s Ghacks.net for three more:


      the way i’m running (on purpose) makes worries about viruses non existent
      the big eye in the sky can look all it wants (it is going to anyway) so when i’m feeling extra frisky and bored i will lead it back onto itself… kinda like the endless loop (yes i did) on the old mainframe arpanet… see:https://en.wikipedia.org/wiki/ARPANET if interested.
      anyway, enough from me (for now) and thanks again for having my back whilst on our journey riding the wild interweb today…

    • #94520

      I followed all the suggestions and it seems that all but one of my dozens of open tabs work normally. However, feedly.com gave me the dreaded “Oops. Something went wrong!” page. As feedly is my most accessed site, I may have to copy back my saved profile. Bummer! BTW, it is not that feedly is coincidentally having problems, as it shows up OK in Chrome.
      Any ideas which of the many settings may have borked feedly?

      • #94530

        It’s more than likely a Additional Privacy Tweak, just default the settings for
        2 TRUE, 3 TRUE & 6 FALSE then try again.
        Implement one at a time and check it works (process of elimination)

        Keep IT Lean, Clean and Mean!
    • #94536

      It might also be worth unticking ‘play drm content’ if you’re not using it. I also unticked the ‘block dangerous and deceptive content’ option under security because that communicates back to the google mothership – https://support.mozilla.org/t5/Protect-your-privacy/How-does-built-in-Phishing-and-Malware-Protection-work/ta-p/9395 – i have enough other protections in place for me not to be too concerned with this but ymmv.


      1 user thanked author for this post.
    • #94549

      Nice job. For those of us not intimately familiar with FireFox it’s nice to have a targeted list with some explanations.


      2 users thanked author for this post.
    • #94587

      The top two security tweaks are the most important LOGJAM & POODLE even if they are set correctly without changing them, it’s better to check anyway.

      thanks for the advise n.n/
      i’m using FF ESR and logjam “problem” is present, now is fixed (yeah).
      (somebody maybe ask… why im using esr? it’s because i feel more stable tan “normal” version)

    • #94763

      Backing Up Firefox Profiles both when Firefox and its Extensions are Available and when Firefox and its Extensions are Not Available:

      For Windows, Mac and Linux, these instructions look good:

      What differs is the exact location of the Mozilla or Firefox Profile Directories, and the kinds of permissions and hidden attributes which need to be considered for a successful copy-paste backup procedure.

      Good storage options include a separate partition, a USB device, or an external drive. Preferably with an extra copy on an external drive just in case.

      Both backing up and restoring are simple copy-paste operations.

      BTW, Firefox and Chrome, Edge and Internet Explorer, all by default now exclude the insecure cipher sets which logjam and poodle relied on. No internal tweaking is required unless you are using a site which still relies on older, insecure cipher suites. Which no one should be doing now. The same applies to the TLS and SSL settings involved in these attacks.

      I personally do use Ghostery, Abine Blur, HTTPS Everywhere and an extension to block HTML autoplay, for security and privacy. If NoScript is added, pretty much all telemetry and DOM and persistent cookie tracking can be blocked. (This involves using some Extension settings which are not set by default. Also, Click And Clean Extension has some settings panels, but these are more useful for Chrome — see below — than for Firefox.)

      Tweaking the Firefox config. settings may bork the browser or make some sites unusable, so this is not my recommended action. It’s a lot easier to reset, suspend or disable an extension than to reconfigure a borked config. file.

      We should develop a KB article here about the changes in Chrome 57 with regard to Flash Player and Plugins controls. Most former Chrome Plugins have been moved to Extensions. There are also security settings which have been moved into little icons in the Location Bar in Chrome 57.

      These changes have caused a lot of finger-pointing, false accusations of loss of user controls and general confusion among Chrome users. I am still sorting through these Chrome changes. And unlike Firefox, if you mess with the Chrome configuration settings, you have no easy way to back up and restore these settings. Which is why the Chrome://Plugins page is no longer available to users.

      -- rc primak

      1 user thanked author for this post.
    • #94807

      hello n.n
      what about “about:telemetry” option? does help in something?
      sorry for many questions…

      • #94813

        about:telemetry is a checklist of all telemetry data within Firefox being sent to Mozilla.
        Ideally (as I have), all the fields have (no data collected) indicating nothing being sent.

        There are many other informative about protocols listed below:

        about:about takes you directly to all of these in link form.

        about: Displays version and build information and links to the contributors, licensing information and build configuration
        about:accounts Page used by the Sync feature
        about:addons Add-ons Manager
        about:app-manager App Manager
        about:buildconfig Displays the configuration and platform used to build Firefox
        about:cache Displays information about the memory, disk, and appcache
        about:compartments Displayed information about compartments; since Firefox 26, that information can be found in the “Other Measurements” section of about:memory.
        about:config Provides a way to inspect and change Firefox preferences and settings
        about:crashes Lists all crashes, which happened during the runtime of Firefox (in case the user enabled the crash reporter)
        about:credits Lists all contributors to the Firefox project
        about:customizing Switches to the customization page, which allows to customize Firefox’ UI
        about:downloads Displays all downloads done within Firefox
        about:healthreport Displays performance information of Firefox (in case the user enabled the health report)
        about:home Start page of Firefox when opening a new window
        about:license Displays licensing information
        about:logo Firefox logo
        about:memory Provides a way to display memory usage, save it as report and run the GC and CC
        about:mozilla Special page showing a message from “The Book of Mozilla”
        about:networking Displays networking information
        about:newtab Start page when opening a new tab
        about:permissions Provides a way to display and manage website permissions. Removed in Firefox 45 (bug 933917)
        about:plugins Displays information about installed plugins
        about:preferences Firefox settings (also available through Firefox menu > Options)
        about:privatebrowsing Start page when opening a private window
        about:reader Indicates a web page has Firefox Reader View turned on. See Firefox Reader View for clutter-free web pages
        about:rights Displays rights information
        about:robots Special page showing notes about robots
        about:sessionrestore Session restoration (displayed after a Firefox crash)
        about:support Troubleshooting information (also available through Firefox menu > ? (question mark) > Troubleshooting Information)
        about:sync-log Displays a synchronization protocol related to the Sync feature
        about:sync-progress Page displayed after the Sync feature got set up
        about:sync-tabs Lists tabs available for synchronization related to the Sync feature
        about:telemetry Displays telemetry data collected and sent to Mozilla while Firefox is running (in case the user enabled telemetry)
        about:webrtc Information about WebRTC usage
        about:welcomeback Information page displayed after Firefox is reset

        Keep IT Lean, Clean and Mean!
        3 users thanked author for this post.
    • #95278

      Re: Additional Privacy Tweaks #5

      geo.wifi.uri set to

      My setting is [http://localhost:8888/]
      Does this need to be changed?

    • #95310

      Additional Privacy Tweaks Note 3):
      Setting the ‘dom.storage.enabled’ entry to false can “break” some websites as they are reliant on DOM storage tracking.
      Changing this setting should therefore be done with caution.
      If you have done this and find website does not display, revert setting back to default.

      Keep IT Lean, Clean and Mean!
      1 user thanked author for this post.
    • #109333

      An additional security tweak for a link issue which has recently resurfaced using language coding for weblinks.

      The problem: Some letters in other languages like Cyrillic are different but look almost identical. You can get identical-looking versions of “a”, “B”, “c”, “i”, “l”, “O” and “p,” among others.

      So by combining the codes for these other letters with non-coded letters you can appear to spell out a word like “apple,” therefore tricking people into visiting a different website from the one they think they are visiting.

      To avoid this go to:


      set the following string to TRUE


      Source: Here

      In depth info: Link

      Keep IT Lean, Clean and Mean!
      4 users thanked author for this post.
    • #118275

      I want to point out that anyone resetting “dom.storage.enabled” = False, will encounter an issue with the Microsoft Catalog.

      Thanks to Microfix for mentioning potential issues regarding websites. It helped me identify the change that broke MS catalog.

      I use the MSCat for Group B downloads, so for others in B, set this to default (True).

      This is what you get with “False” set.



      1 user thanked author for this post.
    • #186385

      For the truly adventurous, here’s a link to the ghacks website and an article by Martin Brinkmann on all kinds of Firefox tweaks for privacy and security. Remember, YMMV and some settings, such as those mentioned in posts above, may “break” certain or possibly most websites, so tread with caution. I suggest reading the explanations above each section to see what’s involved with that section to see if you really need to pay attention to it or if you feel you can ignore it.

      The link was on this thread some time ago, but must’ve bitten the big one with the server migrations of recent months. If it’s still listed above, my sincerest apologies and feel free to delete this post.

      Ok, here’s the link:https://www.ghacks.net/2015/08/18/a-comprehensive-list-of-firefox-privacy-and-security-settings/

      As noted on the page itself, the list has been updated to reflect certain changes in newer editions of Firefox. Latest changes were last year, 2017. Enjoy!

    • #204269

      For Firefox Quantum 61.0 or greater, change the following attributes within about:config

      1) Type: security.tls.version.min set to 3 (1 = TLS 1.0 / 2 = TLS 1.1/ 3 = TLS 1.2)
      2) Type: security.tls.version.max set to 4 (Enables TLS 1.3)

      Remember: to take note of your existing settings prior to changing, should you need to revert back due to some websites not functioning properly.

      Keep IT Lean, Clean and Mean!
      1 user thanked author for this post.
    • #240902
    • #314783

      I found this string geo.provider.ms-windows-location set to true in Waterfox for Windows, so if found Firefox users should toggle that to false as another casual defense against geographical location queries.

    • #342423

      This is a great resource —any chance of an update? Firefox ver 65.02  currently.

      Thank you

    • #1915496

      ? says:

      building yet another linux \w Firefox (loads more fun than watching the pain(t) dry on Microsoft) and stumbled upon thesse 3 additional security\telemetry tweaks:



      and: ui.submenu.Delay (=0)  just for fun!


    • #1917021

      ? says:

      here is a way to disable “dom.push.enabled in “about:config:” in FF from a few years ago:


      there used to be a setting in about:preferences. i turned off APPLE PUSH in itunes long ago. i object to being “pushed” especially if i’m not sure what i’m being “pushed,” into…


    • #2124421

      Firefox now shows what telemetry data it’s collecting about you
      Users can no go to about:telemetry and see what Mozilla is collecting about their Firefox installs.

      By Catalin Cimpanu | February 1, 2020

      There is now a special page in the Firefox browser where users can see what telemetry data Mozilla is collecting from their browser.

      Accessible by typing about:telemetry in the browser’s URL address bar, this new section is a recent addition to Firefox.

      The page shows deeply technical information about browser settings, installed add-ons, OS/hardware information, browser session details, and running processes.

      However, if users are still uncomfortable with allowing Mozilla to collect even the most basic details about their browser install, they can disable Firefox’s telemetry feature from the browser’s settings section, at about:preferences#privacy in the “Firefox Data Collection and Use” section

      Read the full article here

      • #2124432

        ? says:

        thank you, Kirsty! i have “Firefox Data Collection And Use”, (allow Firefox…both unchecked) in “Preferences, Privacy & Security,” hence showing “disabled,” in about:telemetry. FF 72.0.2. so nothing for me to see there…

    Viewing 20 reply threads
    Reply To: 3000003: Firefox – additional security, telemetry and privacy tweaks

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