/* INDEX: 0100: STARTUP 0200: GEOLOCATION / LANGUAGE / LOCALE 0300: QUIETER FOX 0400: SAFE BROWSING 0600: BLOCK IMPLICIT OUTBOUND 0700: DNS / DoH / PROXY / SOCKS / IPv6 0800: LOCATION BAR / SEARCH BAR / SUGGESTIONS / HISTORY / FORMS 0900: PASSWORDS 1000: DISK AVOIDANCE 1200: HTTPS (SSL/TLS / OCSP / CERTS / HPKP) 1400: FONTS 1600: HEADERS / REFERERS 1700: CONTAINERS 2000: PLUGINS / MEDIA / WEBRTC 2400: DOM (DOCUMENT OBJECT MODEL) 2600: MISCELLANEOUS 2700: ETP (ENHANCED TRACKING PROTECTION) 2800: SHUTDOWN & SANITIZING 4500: RFP (RESIST FINGERPRINTING) 5000: OPTIONAL OPSEC 5500: OPTIONAL HARDENING 6000: DON'T TOUCH 7000: DON'T BOTHER 8000: DON'T BOTHER: FINGERPRINTING 9000: NON-PROJECT RELATED 9999: DEPRECATED / REMOVED / LEGACY / RENAMED ******/ /* START: internal custom pref to test for syntax errors * [NOTE] Not all syntax errors cause parsing to abort i.e. reaching the last debug pref * no longer necessarily means that all prefs have been applied. Check the console right * after startup for any warnings/error messages related to non-applied prefs * [1] https://blog.mozilla.org/nnethercote/2018/03/09/a-new-preferences-parser-for-firefox/ ***/ user_pref("_user.js.parrot", "START: Oh yes, the Norwegian Blue... what's wrong with it?"); /* 0000: disable about:config warning ***/ user_pref("browser.aboutConfig.showWarning", false); /*** [SECTION 0100]: STARTUP ***/ user_pref("_user.js.parrot", "0100 syntax error: the parrot's dead!"); /* 0102: set startup page [SETUP-CHROME] * 0=blank, 1=home, 2=last visited page, 3=resume previous session * [NOTE] Session Restore is cleared with history (2811), and not used in Private Browsing mode * [SETTING] General>Startup>Restore previous session ***/ user_pref("browser.startup.page", 0); /* 0103: set HOME+NEWWINDOW page * about:home=Firefox Home (default, see 0105), custom URL, about:blank * [SETTING] Home>New Windows and Tabs>Homepage and new windows ***/ user_pref("browser.startup.homepage", "about:blank"); /* 0104: set NEWTAB page * true=Firefox Home (default, see 0105), false=blank page * [SETTING] Home>New Windows and Tabs>New tabs ***/ user_pref("browser.newtabpage.enabled", false); /* 0105: disable sponsored content on Firefox Home (Activity Stream) * [SETTING] Home>Firefox Home Content ***/ user_pref("browser.newtabpage.activity-stream.showSponsored", false); // [FF58+] Pocket > Sponsored Stories user_pref("browser.newtabpage.activity-stream.showSponsoredTopSites", false); // [FF83+] Sponsored shortcuts /* 0106: clear default topsites * [NOTE] This does not block you from adding your own ***/ user_pref("browser.newtabpage.activity-stream.default.sites", ""); /*** [SECTION 0200]: GEOLOCATION / LANGUAGE / LOCALE ***/ user_pref("_user.js.parrot", "0200 syntax error: the parrot's definitely deceased!"); /* 0201: use Mozilla geolocation service instead of Google if permission is granted [FF74+] * Optionally enable logging to the console (defaults to false) ***/ user_pref("geo.provider.network.url", "https://location.services.mozilla.com/v1/geolocate?key=%MOZILLA_API_KEY%"); /* 0202: disable using the OS's geolocation service ***/ user_pref("geo.provider.use_gpsd", false); user_pref("geo.provider.use_geoclue", false); // [FF102+] /* 0210: set preferred language for displaying pages * [SETTING] General>Language and Appearance>Language>Choose your preferred language... * [TEST] https://addons.mozilla.org/about ***/ user_pref("intl.accept_languages", "en-US, en"); /* 0211: use en-US locale regardless of the system or region locale * [SETUP-WEB] May break some input methods e.g xim/ibus for CJK languages [1] * [1] https://bugzilla.mozilla.org/buglist.cgi?bug_id=867501,1629630 ***/ user_pref("javascript.use_us_english_locale", true); // [HIDDEN PREF] /*** [SECTION 0300]: QUIETER FOX ***/ user_pref("_user.js.parrot", "0300 syntax error: the parrot's not pinin' for the fjords!"); /** RECOMMENDATIONS ***/ /* 0320: disable recommendation pane in about:addons (uses Google Analytics) ***/ user_pref("extensions.getAddons.showPane", false); // [HIDDEN PREF] /* 0321: disable recommendations in about:addons' Extensions and Themes panes [FF68+] ***/ user_pref("extensions.htmlaboutaddons.recommendations.enabled", false); /* 0322: disable personalized Extension Recommendations in about:addons and AMO [FF65+] * [NOTE] This pref has no effect when Health Reports (0331) are disabled * [SETTING] Privacy & Security>Firefox Data Collection & Use>Allow Firefox to make personalized extension recommendations * [1] https://support.mozilla.org/kb/personalized-extension-recommendations ***/ user_pref("browser.discovery.enabled", false); /** TELEMETRY ***/ /* 0330: disable new data submission [FF41+] * If disabled, no policy is shown or upload takes place, ever * [1] https://bugzilla.mozilla.org/1195552 ***/ user_pref("datareporting.policy.dataSubmissionEnabled", false); /* 0331: disable Health Reports * [SETTING] Privacy & Security>Firefox Data Collection & Use>Allow Firefox to send technical... data ***/ user_pref("datareporting.healthreport.uploadEnabled", false); /* 0332: disable telemetry * The "unified" pref affects the behavior of the "enabled" pref * - If "unified" is false then "enabled" controls the telemetry module * - If "unified" is true then "enabled" only controls whether to record extended data * [NOTE] "toolkit.telemetry.enabled" is now LOCKED to reflect prerelease (true) or release builds (false) [2] * [1] https://firefox-source-docs.mozilla.org/toolkit/components/telemetry/telemetry/internals/preferences.html * [2] https://medium.com/georg-fritzsche/data-preference-changes-in-firefox-58-2d5df9c428b5 ***/ user_pref("toolkit.telemetry.unified", false); user_pref("toolkit.telemetry.enabled", false); // see [NOTE] user_pref("toolkit.telemetry.server", "data:,"); user_pref("toolkit.telemetry.archive.enabled", false); user_pref("toolkit.telemetry.newProfilePing.enabled", false); // [FF55+] user_pref("toolkit.telemetry.shutdownPingSender.enabled", false); // [FF55+] user_pref("toolkit.telemetry.updatePing.enabled", false); // [FF56+] user_pref("toolkit.telemetry.bhrPing.enabled", false); // [FF57+] Background Hang Reporter user_pref("toolkit.telemetry.firstShutdownPing.enabled", false); // [FF57+] /* 0333: disable Telemetry Coverage * [1] https://blog.mozilla.org/data/2018/08/20/effectively-measuring-search-in-firefox/ ***/ user_pref("toolkit.telemetry.coverage.opt-out", true); // [HIDDEN PREF] user_pref("toolkit.coverage.opt-out", true); // [FF64+] [HIDDEN PREF] user_pref("toolkit.coverage.endpoint.base", ""); /* 0334: disable PingCentre telemetry (used in several System Add-ons) [FF57+] * Defense-in-depth: currently covered by 0331 ***/ user_pref("browser.ping-centre.telemetry", false); /* 0335: disable Firefox Home (Activity Stream) telemetry ***/ user_pref("browser.newtabpage.activity-stream.feeds.telemetry", false); user_pref("browser.newtabpage.activity-stream.telemetry", false); /** STUDIES ***/ /* 0340: disable Studies * [SETTING] Privacy & Security>Firefox Data Collection & Use>Allow Firefox to install and run studies ***/ user_pref("app.shield.optoutstudies.enabled", false); /* 0341: disable Normandy/Shield [FF60+] * Shield is a telemetry system that can push and test "recipes" * [1] https://mozilla.github.io/normandy/ ***/ user_pref("app.normandy.enabled", false); user_pref("app.normandy.api_url", ""); /** CRASH REPORTS ***/ /* 0350: disable Crash Reports ***/ user_pref("breakpad.reportURL", ""); user_pref("browser.tabs.crashReporting.sendReport", false); // [FF44+] /* 0351: enforce no submission of backlogged Crash Reports [FF58+] * [SETTING] Privacy & Security>Firefox Data Collection & Use>Allow Firefox to send backlogged crash reports ***/ user_pref("browser.crashReports.unsubmittedCheck.autoSubmit2", false); // [DEFAULT: false] /** OTHER ***/ /* 0360: disable Captive Portal detection * [1] https://www.eff.org/deeplinks/2017/08/how-captive-portals-interfere-wireless-security-and-privacy ***/ user_pref("captivedetect.canonicalURL", ""); user_pref("network.captive-portal-service.enabled", false); // [FF52+] /* 0361: disable Network Connectivity checks [FF65+] * [1] https://bugzilla.mozilla.org/1460537 ***/ user_pref("network.connectivity-service.enabled", false); /*** [SECTION 0400]: SAFE BROWSING (SB) SB has taken many steps to preserve privacy. If required, a full url is never sent to Google, only a part-hash of the prefix, hidden with noise of other real part-hashes. Firefox takes measures such as stripping out identifying parameters and since SBv4 (FF57+) doesn't even use cookies. (#Turn on browser.safebrowsing.debug to monitor this activity) [1] https://feeding.cloud.geek.nz/posts/how-safe-browsing-works-in-firefox/ [2] https://wiki.mozilla.org/Security/Safe_Browsing [3] https://support.mozilla.org/kb/how-does-phishing-and-malware-protection-work [4] https://educatedguesswork.org/posts/safe-browsing-privacy/ ***/ user_pref("_user.js.parrot", "0400 syntax error: the parrot's passed on!"); /* 0401: disable SB (Safe Browsing) * [WARNING] Do this at your own risk! These are the master switches * [SETTING] Privacy & Security>Security>... Block dangerous and deceptive content ***/ user_pref("browser.safebrowsing.malware.enabled", false); user_pref("browser.safebrowsing.phishing.enabled", false); /* 0402: disable SB checks for downloads (both local lookups + remote) * This is the master switch for the safebrowsing.downloads* prefs (0403, 0404) * [SETTING] Privacy & Security>Security>... "Block dangerous downloads" ***/ user_pref("browser.safebrowsing.downloads.enabled", false); /* 0403: disable SB checks for downloads (remote) * To verify the safety of certain executable files, Firefox may submit some information about the * file, including the name, origin, size and a cryptographic hash of the contents, to the Google * Safe Browsing service which helps Firefox determine whether or not the file should be blocked * [SETUP-SECURITY] If you do not understand this, or you want this protection, then override this ***/ user_pref("browser.safebrowsing.downloads.remote.enabled", false); user_pref("browser.safebrowsing.downloads.remote.url", ""); // Defense-in-depth /* 0404: disable SB checks for unwanted software * [SETTING] Privacy & Security>Security>... "Warn you about unwanted and uncommon software" ***/ user_pref("browser.safebrowsing.downloads.remote.block_potentially_unwanted", false); user_pref("browser.safebrowsing.downloads.remote.block_uncommon", false); /* 0405: disable "ignore this warning" on SB warnings [FF45+] * If clicked, it bypasses the block for that session. This is a means for admins to enforce SB * [TEST] see https://github.com/arkenfox/user.js/wiki/Appendix-A-Test-Sites#-mozilla * [1] https://bugzilla.mozilla.org/1226490 ***/ user_pref("browser.safebrowsing.allowOverride", false); /*** [SECTION 0600]: BLOCK IMPLICIT OUTBOUND [not explicitly asked for - e.g. clicked on] ***/ user_pref("_user.js.parrot", "0600 syntax error: the parrot's no more!"); /* 0601: disable link prefetching * [1] https://developer.mozilla.org/docs/Web/HTTP/Link_prefetching_FAQ ***/ user_pref("network.prefetch-next", false); /* 0602: disable DNS prefetching * [1] https://developer.mozilla.org/docs/Web/HTTP/Headers/X-DNS-Prefetch-Control ***/ user_pref("network.dns.disablePrefetch", true); /* 0603: disable predictor / prefetching ***/ user_pref("network.predictor.enabled", false); user_pref("network.predictor.enable-prefetch", false); // [FF48+] [DEFAULT: false] /* 0604: disable link-mouseover opening connection to linked server * [1] https://news.slashdot.org/story/15/08/14/2321202/how-to-quash-firefoxs-silent-requests ***/ user_pref("network.http.speculative-parallel-limit", 0); /* 0605: disable mousedown speculative connections on bookmarks and history [FF98+] ***/ user_pref("browser.places.speculativeConnect.enabled", false); /* 0610: enforce no "Hyperlink Auditing" (click tracking) * [1] https://www.bleepingcomputer.com/news/software/major-browsers-to-prevent-disabling-of-click-tracking-privacy-risk/ ***/ user_pref("browser.send_pings", false); // [DEFAULT: false] /*** [SECTION 0700]: DNS / DoH / PROXY / SOCKS / IPv6 ***/ user_pref("_user.js.parrot", "0700 syntax error: the parrot's given up the ghost!"); /* 0701: disable IPv6 * IPv6 can be abused, especially with MAC addresses, and can leak with VPNs: assuming * your ISP and/or router and/or website is IPv6 capable. Most sites will fall back to IPv4 * [SETUP-WEB] PR_CONNECT_RESET_ERROR: this pref *might* be the cause * [STATS] Firefox telemetry (Feb 2023) shows ~9% of successful connections are IPv6 * [NOTE] This is an application level fallback. Disabling IPv6 is best done at an * OS/network level, and/or configured properly in VPN setups. If you are not masking your IP, * then this won't make much difference. If you are masking your IP, then it can only help. * [NOTE] PHP defaults to IPv6 with "localhost". Use "php -S 127.0.0.1:PORT" * [TEST] https://ipleak.org/ * [1] https://www.internetsociety.org/tag/ipv6-security/ (Myths 2,4,5,6) ***/ user_pref("network.dns.disableIPv6", true); /* 0702: set the proxy server to do any DNS lookups when using SOCKS * e.g. in Tor, this stops your local DNS server from knowing your Tor destination * as a remote Tor node will handle the DNS request * [1] https://trac.torproject.org/projects/tor/wiki/doc/TorifyHOWTO/WebBrowsers ***/ user_pref("network.proxy.socks_remote_dns", true); /* 0703: disable using UNC (Uniform Naming Convention) paths [FF61+] * [SETUP-CHROME] Can break extensions for profiles on network shares * [1] https://gitlab.torproject.org/tpo/applications/tor-browser/-/issues/26424 ***/ user_pref("network.file.disable_unc_paths", true); // [HIDDEN PREF] /* 0704: disable GIO as a potential proxy bypass vector * Gvfs/GIO has a set of supported protocols like obex, network, archive, computer, * dav, cdda, gphoto2, trash, etc. By default only sftp is accepted (FF87+) * [1] https://bugzilla.mozilla.org/1433507 * [2] https://en.wikipedia.org/wiki/GVfs * [3] https://en.wikipedia.org/wiki/GIO_(software) ***/ user_pref("network.gio.supported-protocols", ""); // [HIDDEN PREF] /* 0705: disable proxy direct failover for system requests [FF91+] * [WARNING] Default true is a security feature against malicious extensions [1] * [SETUP-CHROME] If you use a proxy and you trust your extensions * [1] https://blog.mozilla.org/security/2021/10/25/securing-the-proxy-api-for-firefox-add-ons/ ***/ // user_pref("network.proxy.failover_direct", false); /* 0706: disable proxy bypass for system request failures [FF95+] * RemoteSettings, UpdateService, Telemetry [1] * [WARNING] If false, this will break the fallback for some security features * [SETUP-CHROME] If you use a proxy and you understand the security impact * [1] https://bugzilla.mozilla.org/buglist.cgi?bug_id=1732792,1733994,1733481 ***/ // user_pref("network.proxy.allow_bypass", false); /* 0710: disable DNS-over-HTTPS (DoH) rollout [FF60+] * 0=default, 2=increased (TRR (Trusted Recursive Resolver) first), 3=max (TRR only), 5=off * see "doh-rollout.home-region": USA 2019, Canada 2021, Russia/Ukraine 2022 [3] * [SETTING] Privacy & Security>DNS over HTTPS * [1] https://hacks.mozilla.org/2018/05/a-cartoon-intro-to-dns-over-https/ * [2] https://wiki.mozilla.org/Security/DOH-resolver-policy * [3] https://support.mozilla.org/en-US/kb/firefox-dns-over-https * [4] https://www.eff.org/deeplinks/2020/12/dns-doh-and-odoh-oh-my-year-review-2020 ***/ // user_pref("network.trr.mode", 5); /*** [SECTION 0800]: LOCATION BAR / SEARCH BAR / SUGGESTIONS / HISTORY / FORMS ***/ user_pref("_user.js.parrot", "0800 syntax error: the parrot's ceased to be!"); /* 0801: disable location bar using search * Don't leak URL typos to a search engine, give an error message instead * Examples: "secretplace,com", "secretplace/com", "secretplace com", "secret place.com" * [NOTE] This does not affect explicit user action such as using search buttons in the * dropdown, or using keyword search shortcuts you configure in options (e.g. "d" for DuckDuckGo) * [SETUP-CHROME] Override this if you trust and use a privacy respecting search engine ***/ user_pref("keyword.enabled", false); /* 0802: disable location bar domain guessing * domain guessing intercepts DNS "hostname not found errors" and resends a * request (e.g. by adding www or .com). This is inconsistent use (e.g. FQDNs), does not work * via Proxy Servers (different error), is a flawed use of DNS (TLDs: why treat .com * as the 411 for DNS errors?), privacy issues (why connect to sites you didn't * intend to), can leak sensitive data (e.g. query strings: e.g. Princeton attack), * and is a security risk (e.g. common typos & malicious sites set up to exploit this) ***/ user_pref("browser.fixup.alternate.enabled", false); // [DEFAULT: false FF104+] /* 0804: disable live search suggestions * [NOTE] Both must be true for the location bar to work * [SETUP-CHROME] Override these if you trust and use a privacy respecting search engine * [SETTING] Search>Provide search suggestions | Show search suggestions in address bar results ***/ user_pref("browser.search.suggest.enabled", false); user_pref("browser.urlbar.suggest.searches", false); /* 0805: disable location bar making speculative connections [FF56+] * [1] https://bugzilla.mozilla.org/1348275 ***/ user_pref("browser.urlbar.speculativeConnect.enabled", false); /* 0806: disable location bar leaking single words to a DNS provider **after searching** [FF78+] * 0=never resolve, 1=use heuristics, 2=always resolve * [1] https://bugzilla.mozilla.org/1642623 ***/ user_pref("browser.urlbar.dnsResolveSingleWordsAfterSearch", 0); // [DEFAULT: 0 FF104+] /* 0807: disable location bar contextual suggestions [FF92+] * [SETTING] Privacy & Security>Address Bar>Suggestions from... * [1] https://blog.mozilla.org/data/2021/09/15/data-and-firefox-suggest/ ***/ user_pref("browser.urlbar.suggest.quicksuggest.nonsponsored", false); // [FF95+] user_pref("browser.urlbar.suggest.quicksuggest.sponsored", false); /* 0808: disable tab-to-search [FF85+] * Alternatively, you can exclude on a per-engine basis by unchecking them in Options>Search * [SETTING] Privacy & Security>Address Bar>When using the address bar, suggest>Search engines ***/ user_pref("browser.urlbar.suggest.engines", false); /* 0810: disable search and form history * [SETUP-WEB] Be aware that autocomplete form data can be read by third parties [1][2] * [NOTE] We also clear formdata on exit (2811) * [SETTING] Privacy & Security>History>Custom Settings>Remember search and form history * [1] https://blog.mindedsecurity.com/2011/10/autocompleteagain.html * [2] https://bugzilla.mozilla.org/381681 ***/ user_pref("browser.formfill.enable", false); /* 0820: disable coloring of visited links * [SETUP-HARDEN] Bulk rapid history sniffing was mitigated in 2010 [1][2]. Slower and more expensive * redraw timing attacks were largely mitigated in FF77+ [3]. Using RFP (4501) further hampers timing * attacks. Don't forget clearing history on exit (2811). However, social engineering [2#limits][4][5] * and advanced targeted timing attacks could still produce usable results * [1] https://developer.mozilla.org/docs/Web/CSS/Privacy_and_the_:visited_selector * [2] https://dbaron.org/mozilla/visited-privacy * [3] https://bugzilla.mozilla.org/1632765 * [4] https://earthlng.github.io/testpages/visited_links.html (see github wiki APPENDIX A on how to use) * [5] https://lcamtuf.blogspot.com/2016/08/css-mix-blend-mode-is-bad-for-keeping.html ***/ // user_pref("layout.css.visited_links_enabled", false); /*** [SECTION 0900]: PASSWORDS [1] https://support.mozilla.org/kb/use-primary-password-protect-stored-logins-and-pas ***/ user_pref("_user.js.parrot", "0900 syntax error: the parrot's expired!"); /* 0903: disable auto-filling username & password form fields * can leak in cross-site forms *and* be spoofed * [NOTE] Username & password is still available when you enter the field * [SETTING] Privacy & Security>Logins and Passwords>Autofill logins and passwords * [1] https://freedom-to-tinker.com/2017/12/27/no-boundaries-for-user-identities-web-trackers-exploit-browser-login-managers/ * [2] https://homes.esat.kuleuven.be/~asenol/leaky-forms/ ***/ user_pref("signon.autofillForms", false); /* 0904: disable formless login capture for Password Manager [FF51+] ***/ user_pref("signon.formlessCapture.enabled", false); /* 0905: limit (or disable) HTTP authentication credentials dialogs triggered by sub-resources [FF41+] * hardens against potential credentials phishing * 0 = don't allow sub-resources to open HTTP authentication credentials dialogs * 1 = don't allow cross-origin sub-resources to open HTTP authentication credentials dialogs * 2 = allow sub-resources to open HTTP authentication credentials dialogs (default) ***/ user_pref("network.auth.subresource-http-auth-allow", 1); /*** [SECTION 1000]: DISK AVOIDANCE ***/ user_pref("_user.js.parrot", "1000 syntax error: the parrot's gone to meet 'is maker!"); /* 1001: disable disk cache * [SETUP-CHROME] If you think disk cache helps perf, then feel free to override this * [NOTE] We also clear cache on exit (2811) ***/ user_pref("browser.cache.disk.enable", false); /* 1002: disable media cache from writing to disk in Private Browsing * [NOTE] MSE (Media Source Extensions) are already stored in-memory in PB ***/ user_pref("browser.privatebrowsing.forceMediaMemoryCache", true); // [FF75+] user_pref("media.memory_cache_max_size", 65536); /* 1003: disable storing extra session data [SETUP-CHROME] * define on which sites to save extra session data such as form content, cookies and POST data * 0=everywhere, 1=unencrypted sites, 2=nowhere ***/ user_pref("browser.sessionstore.privacy_level", 2); /*** [SECTION 1200]: HTTPS (SSL/TLS / OCSP / CERTS / HPKP) Your cipher and other settings can be used in server side fingerprinting [TEST] https://www.ssllabs.com/ssltest/viewMyClient.html [TEST] https://browserleaks.com/ssl [TEST] https://ja3er.com/ [1] https://www.securityartwork.es/2017/02/02/tls-client-fingerprinting-with-bro/ ***/ user_pref("_user.js.parrot", "1200 syntax error: the parrot's a stiff!"); /** SSL (Secure Sockets Layer) / TLS (Transport Layer Security) ***/ /* 1201: require safe negotiation * Blocks connections to servers that don't support RFC 5746 [2] as they're potentially vulnerable to a * MiTM attack [3]. A server without RFC 5746 can be safe from the attack if it disables renegotiations * but the problem is that the browser can't know that. Setting this pref to true is the only way for the * browser to ensure there will be no unsafe renegotiations on the channel between the browser and the server * [SETUP-WEB] SSL_ERROR_UNSAFE_NEGOTIATION: is it worth overriding this for that one site? * [STATS] SSL Labs (Feb 2023) reports over 99.3% of top sites have secure renegotiation [4] * [1] https://wiki.mozilla.org/Security:Renegotiation * [2] https://datatracker.ietf.org/doc/html/rfc5746 * [3] https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2009-3555 * [4] https://www.ssllabs.com/ssl-pulse/ ***/ user_pref("security.ssl.require_safe_negotiation", true); /* 1206: disable TLS1.3 0-RTT (round-trip time) [FF51+] * This data is not forward secret, as it is encrypted solely under keys derived using * the offered PSK. There are no guarantees of non-replay between connections * [1] https://github.com/tlswg/tls13-spec/issues/1001 * [2] https://www.rfc-editor.org/rfc/rfc9001.html#name-replay-attacks-with-0-rtt * [3] https://blog.cloudflare.com/tls-1-3-overview-and-q-and-a/ ***/ user_pref("security.tls.enable_0rtt_data", false); /** OCSP (Online Certificate Status Protocol) [1] https://scotthelme.co.uk/revocation-is-broken/ [2] https://blog.mozilla.org/security/2013/07/29/ocsp-stapling-in-firefox/ ***/ /* 1211: enforce OCSP fetching to confirm current validity of certificates * 0=disabled, 1=enabled (default), 2=enabled for EV certificates only * OCSP (non-stapled) leaks information about the sites you visit to the CA (cert authority) * It's a trade-off between security (checking) and privacy (leaking info to the CA) * [NOTE] This pref only controls OCSP fetching and does not affect OCSP stapling * [SETTING] Privacy & Security>Security>Certificates>Query OCSP responder servers... * [1] https://en.wikipedia.org/wiki/Ocsp ***/ user_pref("security.OCSP.enabled", 1); // [DEFAULT: 1] /* 1212: set OCSP fetch failures (non-stapled, see 1211) to hard-fail * [SETUP-WEB] SEC_ERROR_OCSP_SERVER_ERROR * When a CA cannot be reached to validate a cert, Firefox just continues the connection (=soft-fail) * Setting this pref to true tells Firefox to instead terminate the connection (=hard-fail) * It is pointless to soft-fail when an OCSP fetch fails: you cannot confirm a cert is still valid (it * could have been revoked) and/or you could be under attack (e.g. malicious blocking of OCSP servers) * [1] https://blog.mozilla.org/security/2013/07/29/ocsp-stapling-in-firefox/ * [2] https://www.imperialviolet.org/2014/04/19/revchecking.html ***/ user_pref("security.OCSP.require", true); /** CERTS / HPKP (HTTP Public Key Pinning) ***/ /* 1223: enable strict PKP (Public Key Pinning) * 0=disabled, 1=allow user MiTM (default; such as your antivirus), 2=strict * [SETUP-WEB] MOZILLA_PKIX_ERROR_KEY_PINNING_FAILURE ***/ user_pref("security.cert_pinning.enforcement_level", 2); /* 1224: enable CRLite [FF73+] * 0 = disabled * 1 = consult CRLite but only collect telemetry * 2 = consult CRLite and enforce both "Revoked" and "Not Revoked" results * 3 = consult CRLite and enforce "Not Revoked" results, but defer to OCSP for "Revoked" (FF99+, default FF100+) * [1] https://bugzilla.mozilla.org/buglist.cgi?bug_id=1429800,1670985,1753071 * [2] https://blog.mozilla.org/security/tag/crlite/ ***/ user_pref("security.remote_settings.crlite_filters.enabled", true); user_pref("security.pki.crlite_mode", 2); /** MIXED CONTENT ***/ /* 1241: disable insecure passive content (such as images) on https pages ***/ // user_pref("security.mixed_content.block_display_content", true); // Defense-in-depth (see 1244) /* 1244: enable HTTPS-Only mode in all windows [FF76+] * When the top-level is HTTPS, insecure subresources are also upgraded (silent fail) * [SETTING] to add site exceptions: Padlock>HTTPS-Only mode>On (after "Continue to HTTP Site") * [SETTING] Privacy & Security>HTTPS-Only Mode (and manage exceptions) * [TEST] http://example.com [upgrade] * [TEST] http://httpforever.com/ | http://http.rip [no upgrade] ***/ user_pref("dom.security.https_only_mode", true); // [FF76+] // user_pref("dom.security.https_only_mode_pbm", true); // [FF80+] /* 1245: enable HTTPS-Only mode for local resources [FF77+] ***/ user_pref("dom.security.https_only_mode.upgrade_local", true); /* 1246: disable HTTP background requests [FF82+] * When attempting to upgrade, if the server doesn't respond within 3 seconds, Firefox sends * a top-level HTTP request without path in order to check if the server supports HTTPS or not * This is done to avoid waiting for a timeout which takes 90 seconds * [1] https://bugzilla.mozilla.org/buglist.cgi?bug_id=1642387,1660945 ***/ user_pref("dom.security.https_only_mode_send_http_background_request", false); /** UI (User Interface) ***/ /* 1270: display warning on the padlock for "broken security" (if 1201 is false) * Bug: warning padlock not indicated for subresources on a secure page! [2] * [1] https://wiki.mozilla.org/Security:Renegotiation * [2] https://bugzilla.mozilla.org/1353705 ***/ user_pref("security.ssl.treat_unsafe_negotiation_as_broken", true); /* 1272: display advanced information on Insecure Connection warning pages * only works when it's possible to add an exception * i.e. it doesn't work for HSTS discrepancies (https://subdomain.preloaded-hsts.badssl.com/) * [TEST] https://expired.badssl.com/ ***/ user_pref("browser.xul.error_pages.expert_bad_cert", true); /*** [SECTION 1400]: FONTS ***/ user_pref("_user.js.parrot", "1400 syntax error: the parrot's bereft of life!"); /* 1402: limit font visibility (Windows, Mac, some Linux) [FF94+] * Uses hardcoded lists with two parts: kBaseFonts + kLangPackFonts [1], bundled fonts are auto-allowed * In normal windows: uses the first applicable: RFP (4506) over TP over Standard * In Private Browsing windows: uses the most restrictive between normal and private * 1=only base system fonts, 2=also fonts from optional language packs, 3=also user-installed fonts * [1] https://searchfox.org/mozilla-central/search?path=StandardFonts*.inc ***/ user_pref("layout.css.font-visibility.private", 1); user_pref("layout.css.font-visibility.standard", 1); user_pref("layout.css.font-visibility.trackingprotection", 1); /*** [SECTION 1600]: HEADERS / REFERERS full URI: https://example.com:8888/foo/bar.html?id=1234 scheme+host+port+path: https://example.com:8888/foo/bar.html scheme+host+port: https://example.com:8888 [1] https://feeding.cloud.geek.nz/posts/tweaking-referrer-for-privacy-in-firefox/ ***/ user_pref("_user.js.parrot", "1600 syntax error: the parrot rests in peace!"); /* 1601: control when to send a cross-origin referer * 0=always (default), 1=only if base domains match, 2=only if hosts match * [SETUP-WEB] Breakage: older modems/routers and some sites e.g banks, vimeo, icloud, instagram * If "2" is too strict, then override to "0" and use Smart Referer extension (Strict mode + add exceptions) ***/ user_pref("network.http.referer.XOriginPolicy", 2); /* 1602: control the amount of cross-origin information to send [FF52+] * 0=send full URI (default), 1=scheme+host+port+path, 2=scheme+host+port ***/ user_pref("network.http.referer.XOriginTrimmingPolicy", 2); /*** [SECTION 1700]: CONTAINERS ***/ user_pref("_user.js.parrot", "1700 syntax error: the parrot's bit the dust!"); /* 1701: enable Container Tabs and its UI setting [FF50+] * [SETTING] General>Tabs>Enable Container Tabs * https://wiki.mozilla.org/Security/Contextual_Identity_Project/Containers ***/ user_pref("privacy.userContext.enabled", true); user_pref("privacy.userContext.ui.enabled", true); /* 1702: set behavior on "+ Tab" button to display container menu on left click [FF74+] * [NOTE] The menu is always shown on long press and right click * [SETTING] General>Tabs>Enable Container Tabs>Settings>Select a container for each new tab ***/ // user_pref("privacy.userContext.newTabContainerOnLeftClick.enabled", true); /*** [SECTION 2000]: PLUGINS / MEDIA / WEBRTC ***/ user_pref("_user.js.parrot", "2000 syntax error: the parrot's snuffed it!"); /* 2002: force WebRTC inside the proxy [FF70+] ***/ user_pref("media.peerconnection.ice.proxy_only_if_behind_proxy", true); /* 2003: force a single network interface for ICE candidates generation [FF42+] * When using a system-wide proxy, it uses the proxy interface * [1] https://developer.mozilla.org/en-US/docs/Web/API/RTCIceCandidate * [2] https://wiki.mozilla.org/Media/WebRTC/Privacy ***/ user_pref("media.peerconnection.ice.default_address_only", true); /* 2004: force exclusion of private IPs from ICE candidates [FF51+] * [SETUP-HARDEN] This will protect your private IP even in TRUSTED scenarios after you * grant device access, but often results in breakage on video-conferencing platforms ***/ // user_pref("media.peerconnection.ice.no_host", true); /* 2020: disable GMP (Gecko Media Plugins) * [1] https://wiki.mozilla.org/GeckoMediaPlugins ***/ // user_pref("media.gmp-provider.enabled", false); /* 2021: disable widevine CDM (Content Decryption Module) * [NOTE] This is covered by the EME master switch (2022) ***/ user_pref("media.gmp-widevinecdm.enabled", false); /* 2022: disable all DRM content (EME: Encryption Media Extension) * Optionally hide the setting which also disables the DRM prompt * [SETUP-WEB] e.g. Netflix, Amazon Prime, Hulu, HBO, Disney+, Showtime, Starz, DirectTV * [SETTING] General>DRM Content>Play DRM-controlled content * [TEST] https://bitmovin.com/demos/drm * [1] https://www.eff.org/deeplinks/2017/10/drms-dead-canary-how-we-just-lost-web-what-we-learned-it-and-what-we-need-do-next ***/ user_pref("media.eme.enabled", false); user_pref("browser.eme.ui.enabled", false); /*** [SECTION 2400]: DOM (DOCUMENT OBJECT MODEL) ***/ user_pref("_user.js.parrot", "2400 syntax error: the parrot's kicked the bucket!"); /* 2402: prevent scripts from moving and resizing open windows ***/ user_pref("dom.disable_window_move_resize", true); /*** [SECTION 2600]: MISCELLANEOUS ***/ user_pref("_user.js.parrot", "2600 syntax error: the parrot's run down the curtain!"); /* 2601: prevent accessibility services from accessing your browser [RESTART] * [1] https://support.mozilla.org/kb/accessibility-services ***/ user_pref("accessibility.force_disabled", 1); /* 2603: remove temp files opened with an external application * [1] https://bugzilla.mozilla.org/302433 ***/ user_pref("browser.helperApps.deleteTempFileOnExit", true); /* 2606: disable UITour backend so there is no chance that a remote page can use it ***/ user_pref("browser.uitour.enabled", false); user_pref("browser.uitour.url", ""); // Defense-in-depth /* 2608: reset remote debugging to disabled * [1] https://gitlab.torproject.org/tpo/applications/tor-browser/-/issues/16222 ***/ user_pref("devtools.debugger.remote-enabled", false); // [DEFAULT: false] /* 2615: disable websites overriding Firefox's keyboard shortcuts [FF58+] * 0 (default) or 1=allow, 2=block * [SETTING] to add site exceptions: Ctrl+I>Permissions>Override Keyboard Shortcuts ***/ user_pref("permissions.default.shortcuts", 2); /* 2616: remove special permissions for certain mozilla domains [FF35+] * [1] resource://app/defaults/permissions ***/ user_pref("permissions.manager.defaultsUrl", ""); /* 2617: remove webchannel whitelist ***/ user_pref("webchannel.allowObject.urlWhitelist", ""); /* 2619: use Punycode in Internationalized Domain Names to eliminate possible spoofing * [SETUP-WEB] Might be undesirable for non-latin alphabet users since legitimate IDN's are also punycoded * [TEST] https://www.xn--80ak6aa92e.com/ (www.apple.com) * [1] https://wiki.mozilla.org/IDN_Display_Algorithm * [2] https://en.wikipedia.org/wiki/IDN_homograph_attack * [3] https://cve.mitre.org/cgi-bin/cvekey.cgi?keyword=punycode+firefox * [4] https://www.xudongz.com/blog/2017/idn-phishing/ ***/ user_pref("network.IDN_show_punycode", true); /* 2620: enforce PDFJS, disable PDFJS scripting * This setting controls if the option "Display in Firefox" is available in the setting below * and by effect controls whether PDFs are handled in-browser or externally ("Ask" or "Open With") * [SETTING] General>Applications>Portable Document Format (PDF) * [1] https://cve.mitre.org/cgi-bin/cvekey.cgi?keyword=pdf.js+firefox ***/ user_pref("pdfjs.disabled", true); // [DEFAULT: false] user_pref("pdfjs.enableScripting", false); // [FF86+] /* 2623: disable permissions delegation [FF73+] * Currently applies to cross-origin geolocation, camera, mic and screen-sharing * permissions, and fullscreen requests. Disabling delegation means any prompts * for these will show/use their correct 3rd party origin * [1] https://groups.google.com/forum/#!topic/mozilla.dev.platform/BdFOMAuCGW8/discussion ***/ user_pref("permissions.delegation.enabled", false); /* 2624: disable middle click on new tab button opening URLs or searches using clipboard [FF115+] */ user_pref("browser.tabs.searchclipboardfor.middleclick", false); // [DEFAULT: false NON-LINUX] /** DOWNLOADS ***/ /* 2651: download to download dir * [SETUP-CHROME] On Android this blocks longtapping and saving images * [SETTING] General>Downloads>Always ask you where to save files ***/ user_pref("browser.download.useDownloadDir", true); /* 2652: disable downloads panel opening on every download [FF96+] ***/ user_pref("browser.download.alwaysOpenPanel", false); /* 2653: disable adding downloads to the system's "recent documents" list ***/ user_pref("browser.download.manager.addToRecentDocs", false); /* 2654: enable user interaction for security by always asking how to handle new mimetypes [FF101+] * [SETTING] General>Files and Applications>What should Firefox do with other files ***/ user_pref("browser.download.always_ask_before_handling_new_types", true); /** EXTENSIONS ***/ /* 2660: lock down allowed extension directories * [SETUP-CHROME] This will break extensions, language packs, themes and any other * XPI files which are installed outside of profile and application directories * [1] https://mike.kaply.com/2012/02/21/understanding-add-on-scopes/ * [1] https://archive.is/DYjAM (archived) ***/ user_pref("extensions.enabledScopes", 5); // [HIDDEN PREF] user_pref("extensions.autoDisableScopes", 15); // [DEFAULT: 15] /* 2661: disable bypassing 3rd party extension install prompts [FF82+] * [1] https://bugzilla.mozilla.org/buglist.cgi?bug_id=1659530,1681331 ***/ user_pref("extensions.postDownloadThirdPartyPrompt", false); /* 2662: disable webextension restrictions on certain mozilla domains (you also need 4503) [FF60+] * [1] https://bugzilla.mozilla.org/buglist.cgi?bug_id=1384330,1406795,1415644,1453988 ***/ user_pref("extensions.webextensions.restrictedDomains", ""); // Disable installing from the distribution/extensions dir // We want to install extensions explicitly from policies.json, rather // than silent undocumented installations from the filesystem. // https://support.mozilla.org/en-US/kb/deploying-firefox-with-extensions user_pref("extensions.installDistroAddons", false); /*** [SECTION 2700]: ETP (ENHANCED TRACKING PROTECTION) ***/ user_pref("_user.js.parrot", "2700 syntax error: the parrot's joined the bleedin' choir invisible!"); /* 2701: enable ETP Strict Mode [FF86+] * ETP Strict Mode enables Total Cookie Protection (TCP) * [NOTE] Adding site exceptions disables all ETP protections for that site and increases the risk of * cross-site state tracking e.g. exceptions for SiteA and SiteB means PartyC on both sites is shared * [1] https://blog.mozilla.org/security/2021/02/23/total-cookie-protection/ * [SETTING] to add site exceptions: Urlbar>ETP Shield * [SETTING] to manage site exceptions: Options>Privacy & Security>Enhanced Tracking Protection>Manage Exceptions ***/ user_pref("browser.contentblocking.category", "strict"); /* 2702: disable ETP web compat features [FF93+] * [SETUP-HARDEN] Includes skip lists, heuristics (SmartBlock) and automatic grants * Opener and redirect heuristics are granted for 30 days, see [3] * [1] https://blog.mozilla.org/security/2021/07/13/smartblock-v2/ * [2] https://hg.mozilla.org/mozilla-central/rev/e5483fd469ab#l4.12 * [3] https://developer.mozilla.org/en-US/docs/Web/Privacy/State_Partitioning#storage_access_heuristics ***/ user_pref("privacy.antitracking.enableWebcompat", false); /* 2710: enable state partitioning of service workers [FF96+] ***/ user_pref("privacy.partition.serviceWorkers", true); // [DEFAULT: true FF105+] /* 2720: enable APS (Always Partitioning Storage) ***/ user_pref("privacy.partition.always_partition_third_party_non_cookie_storage", true); // [FF104+] [DEFAULT: true FF109+] user_pref("privacy.partition.always_partition_third_party_non_cookie_storage.exempt_sessionstorage", false); // [FF105+] [DEFAULT: false FF109+] /*** [SECTION 2800]: SHUTDOWN & SANITIZING ***/ user_pref("_user.js.parrot", "2800 syntax error: the parrot's bleedin' demised!"); /* 2810: enable Firefox to clear items on shutdown * [SETTING] Privacy & Security>History>Custom Settings>Clear history when Firefox closes | Settings ***/ user_pref("privacy.sanitize.sanitizeOnShutdown", true); /** SANITIZE ON SHUTDOWN: IGNORES "ALLOW" SITE EXCEPTIONS ***/ /* 2811: set/enforce what items to clear on shutdown (if 2810 is true) [SETUP-CHROME] * [NOTE] If "history" is true, downloads will also be cleared * [NOTE] "sessions": Active Logins: refers to HTTP Basic Authentication [1], not logins via cookies * [1] https://en.wikipedia.org/wiki/Basic_access_authentication ***/ user_pref("privacy.clearOnShutdown.cache", true); // [DEFAULT: true] user_pref("privacy.clearOnShutdown.downloads", true); // [DEFAULT: true] user_pref("privacy.clearOnShutdown.formdata", true); // [DEFAULT: true] user_pref("privacy.clearOnShutdown.history", false); // [DEFAULT: true] user_pref("privacy.clearOnShutdown.sessions", true); // [DEFAULT: true] // user_pref("privacy.clearOnShutdown.siteSettings", false); // [DEFAULT: false] /* 2812: set Session Restore to clear on shutdown (if 2810 is true) [FF34+] * [NOTE] Not needed if Session Restore is not used (0102) or it is already cleared with history (2811) * [NOTE] If true, this prevents resuming from crashes (also see 5008) ***/ // user_pref("privacy.clearOnShutdown.openWindows", true); /** SANITIZE ON SHUTDOWN: RESPECTS "ALLOW" SITE EXCEPTIONS FF103+ ***/ /* 2815: set "Cookies" and "Site Data" to clear on shutdown (if 2810 is true) [SETUP-CHROME] * [NOTE] Exceptions: A "cookie" block permission also controls "offlineApps" (see note below). * serviceWorkers require an "Allow" permission. For cross-domain logins, add exceptions for * both sites e.g. https://www.youtube.com (site) + https://accounts.google.com (single sign on) * [NOTE] "offlineApps": Offline Website Data: localStorage, service worker cache, QuotaManager (IndexedDB, asm-cache) * [WARNING] Be selective with what sites you "Allow", as they also disable partitioning (1767271) * [SETTING] to add site exceptions: Ctrl+I>Permissions>Cookies>Allow (when on the website in question) * [SETTING] to manage site exceptions: Options>Privacy & Security>Permissions>Settings ***/ user_pref("privacy.clearOnShutdown.cookies", true); // Cookies user_pref("privacy.clearOnShutdown.offlineApps", true); // Site Data /** SANITIZE MANUAL: IGNORES "ALLOW" SITE EXCEPTIONS ***/ /* 2820: reset default items to clear with Ctrl-Shift-Del [SETUP-CHROME] * This dialog can also be accessed from the menu History>Clear Recent History * Firefox remembers your last choices. This will reset them when you start Firefox * [NOTE] Regardless of what you set "downloads" to, as soon as the dialog * for "Clear Recent History" is opened, it is synced to the same as "history" ***/ user_pref("privacy.cpd.cache", true); // [DEFAULT: true] user_pref("privacy.cpd.formdata", true); // [DEFAULT: true] user_pref("privacy.cpd.history", true); // [DEFAULT: true] user_pref("privacy.cpd.sessions", true); // [DEFAULT: true] user_pref("privacy.cpd.offlineApps", false); // [DEFAULT: false] user_pref("privacy.cpd.cookies", false); /* 2822: reset default "Time range to clear" for "Clear Recent History" (2820) * Firefox remembers your last choice. This will reset the value when you start Firefox * 0=everything, 1=last hour, 2=last two hours, 3=last four hours, 4=today * [NOTE] Values 5 (last 5 minutes) and 6 (last 24 hours) are not listed in the dropdown, * which will display a blank value, and are not guaranteed to work ***/ user_pref("privacy.sanitize.timeSpan", 0); /*** [SECTION 4500]: RFP (RESIST FINGERPRINTING) RFP covers a wide range of ongoing fingerprinting solutions. It is an all-or-nothing buy in: you cannot pick and choose what parts you want [TEST] https://arkenfox.github.io/TZP/tzp.html [WARNING] DO NOT USE extensions to alter RFP protected metrics 418986 - limit window.screen & CSS media queries (FF41) 1281949 - spoof screen orientation (FF50) 1330890 - spoof timezone as UTC0 (FF55) 1360039 - spoof navigator.hardwareConcurrency as 2 (FF55) FF56 1369303 - spoof/disable performance API 1333651 - spoof User Agent & Navigator API version: android version spoofed as ESR OS: JS spoofed as Windows 10, OS 10.15, Android 10, or Linux | HTTP Headers spoofed as Windows or Android 1369319 - disable device sensor API 1369357 - disable site specific zoom 1337161 - hide gamepads from content 1372072 - spoof network information API as "unknown" when dom.netinfo.enabled = true 1333641 - reduce fingerprinting in WebSpeech API FF57 1369309 - spoof media statistics 1382499 - reduce screen co-ordinate fingerprinting in Touch API 1217290 & 1409677 - enable some fingerprinting resistance for WebGL 1382545 - reduce fingerprinting in Animation API 1354633 - limit MediaError.message to a whitelist FF58+ 1372073 - spoof/block fingerprinting in MediaDevices API (FF59) Spoof: enumerate devices as one "Internal Camera" and one "Internal Microphone" Block: suppresses the ondevicechange event 1039069 - warn when language prefs are not set to "en*" (also see 0210, 0211) (FF59) 1222285 & 1433592 - spoof keyboard events and suppress keyboard modifier events (FF59) Spoofing mimics the content language of the document. Currently it only supports en-US. Modifier events suppressed are SHIFT and both ALT keys. Chrome is not affected. 1337157 - disable WebGL debug renderer info (FF60) 1459089 - disable OS locale in HTTP Accept-Language headers (ANDROID) (FF62) 1479239 - return "no-preference" with prefers-reduced-motion (FF63) 1363508 - spoof/suppress Pointer Events (FF64) 1492766 - spoof pointerEvent.pointerid (FF65) 1485266 - disable exposure of system colors to CSS or canvas (FF67) 1494034 - return "light" with prefers-color-scheme (FF67) 1564422 - spoof audioContext outputLatency (FF70) 1595823 - return audioContext sampleRate as 44100 (FF72) 1607316 - spoof pointer as coarse and hover as none (ANDROID) (FF74) 1621433 - randomize canvas (previously FF58+ returned an all-white canvas) (FF78) 1506364 - return "no-preference" with prefers-contrast (FF80) 1653987 - limit font visibility to bundled and "Base Fonts" (Windows, Mac, some Linux) (FF80) 1461454 - spoof smooth=true and powerEfficient=false for supported media in MediaCapabilities (FF82) 531915 - use fdlibm's sin, cos and tan in jsmath (FF93, ESR91.1) 1756280 - enforce navigator.pdfViewerEnabled as true and plugins/mimeTypes as hard-coded values (FF100) 1692609 - reduce JS timing precision to 16.67ms (previously FF55+ was 100ms) (FF102) 1422237 - return "srgb" with color-gamut (FF110) 1794628 - return "none" with inverted-colors (FF114) ***/ user_pref("_user.js.parrot", "4500 syntax error: the parrot's popped 'is clogs"); /* 4501: enable privacy.resistFingerprinting * [SETUP-WEB] RFP can cause some website breakage: mainly canvas, use a site exception via the urlbar * RFP also has a few side effects: mainly timezone is UTC0, and websites will prefer light theme * [NOTE] pbmode applies if true and the original pref is false * [1] https://bugzilla.mozilla.org/418986 ***/ user_pref("privacy.resistFingerprinting", true); // [FF41+] // user_pref("privacy.resistFingerprinting.pbmode", true); // [FF114+] /* 4502: set new window size rounding max values [FF55+] * [SETUP-CHROME] sizes round down in hundreds: width to 200s and height to 100s, to fit your screen * [1] https://bugzilla.mozilla.org/1330882 ***/ user_pref("privacy.window.maxInnerWidth", 1600); user_pref("privacy.window.maxInnerHeight", 900); /* 4503: disable mozAddonManager Web API [FF57+] * [NOTE] To allow extensions to work on AMO, you also need 2662 * [1] https://bugzilla.mozilla.org/buglist.cgi?bug_id=1384330,1406795,1415644,1453988 ***/ user_pref("privacy.resistFingerprinting.block_mozAddonManager", true); // [HIDDEN PREF FF57-108] /* 4504: enable RFP letterboxing [FF67+] * Dynamically resizes the inner window by applying margins in stepped ranges [2] * If you use the dimension pref, then it will only apply those resolutions. * The format is "width1xheight1, width2xheight2, ..." (e.g. "800x600, 1000x1000") * [SETUP-WEB] This is independent of RFP (4501). If you're not using RFP, or you are but * dislike the margins, then flip this pref, keeping in mind that it is effectively fingerprintable * [WARNING] DO NOT USE: the dimension pref is only meant for testing * [1] https://bugzilla.mozilla.org/1407366 * [2] https://hg.mozilla.org/mozilla-central/rev/6d2d7856e468#l2.32 ***/ user_pref("privacy.resistFingerprinting.letterboxing", true); // [HIDDEN PREF] // user_pref("privacy.resistFingerprinting.letterboxing.dimensions", ""); // [HIDDEN PREF] /* 4505: experimental RFP [FF91+] * [WARNING] DO NOT USE unless testing, see [1] comment 12 * [1] https://bugzilla.mozilla.org/1635603 ***/ // user_pref("privacy.resistFingerprinting.exemptedDomains", "*.example.invalid"); /* 4506: set RFP's font visibility level (1402) [FF94+] ***/ // user_pref("layout.css.font-visibility.resistFingerprinting", 1); // [DEFAULT: 1] /* 4510: disable using system colors * [SETTING] General>Language and Appearance>Fonts and Colors>Colors>Use system colors ***/ user_pref("browser.display.use_system_colors", false); // [DEFAULT: false NON-WINDOWS] /* 4511: enforce non-native widget theme * Security: removes/reduces system API calls, e.g. win32k API [1] * Fingerprinting: provides a uniform look and feel across platforms [2] * [1] https://bugzilla.mozilla.org/1381938 * [2] https://bugzilla.mozilla.org/1411425 ***/ user_pref("widget.non-native-theme.enabled", true); // [DEFAULT: true] /* 4512: enforce links targeting new windows to open in a new tab instead * 1=most recent window or tab, 2=new window, 3=new tab * Stops malicious window sizes and some screen resolution leaks. * You can still right-click a link and open in a new window * [SETTING] General>Tabs>Open links in tabs instead of new windows * [TEST] https://arkenfox.github.io/TZP/tzp.html#screen * [1] https://gitlab.torproject.org/tpo/applications/tor-browser/-/issues/9881 ***/ user_pref("browser.link.open_newwindow", 3); // [DEFAULT: 3] /* 4513: set all open window methods to abide by "browser.link.open_newwindow" (4512) * [1] https://searchfox.org/mozilla-central/source/dom/tests/browser/browser_test_new_window_from_content.js ***/ user_pref("browser.link.open_newwindow.restriction", 0); /* 4520: disable WebGL (Web Graphics Library) * [SETUP-WEB] If you need it then override it. RFP still randomizes canvas for naive scripts ***/ user_pref("webgl.disabled", true); /*** [SECTION 5000]: OPTIONAL OPSEC Disk avoidance, application data isolation, eyeballs... ***/ user_pref("_user.js.parrot", "5000 syntax error: the parrot's taken 'is last bow"); /* 5002: disable memory cache * capacity: -1=determine dynamically (default), 0=none, n=memory capacity in kibibytes ***/ // user_pref("browser.cache.memory.enable", false); // user_pref("browser.cache.memory.capacity", 0); /* 5003: disable saving passwords * [NOTE] This does not clear any passwords already saved * [SETTING] Privacy & Security>Logins and Passwords>Ask to save logins and passwords for websites ***/ user_pref("signon.rememberSignons", false); /* 5004: disable permissions manager from writing to disk [FF41+] [RESTART] * [NOTE] This means any permission changes are session only * [1] https://bugzilla.mozilla.org/967812 ***/ user_pref("permissions.memory_only", true); // [HIDDEN PREF] /* 5005: disable intermediate certificate caching [FF41+] [RESTART] * [NOTE] This affects login/cert/key dbs. The effect is all credentials are session-only. * Saved logins and passwords are not available. Reset the pref and restart to return them ***/ user_pref("security.nocertdb", true); /* 5007: exclude "Undo Closed Tabs" in Session Restore ***/ user_pref("browser.sessionstore.max_tabs_undo", 0); /* 5010: disable location bar suggestion types * [SETTING] Privacy & Security>Address Bar>When using the address bar, suggest ***/ // user_pref("browser.urlbar.suggest.history", false); // user_pref("browser.urlbar.suggest.bookmark", false); // user_pref("browser.urlbar.suggest.openpage", false); user_pref("browser.urlbar.suggest.topsites", false); // [FF78+] /* 5011: disable location bar dropdown * This value controls the total number of entries to appear in the location bar dropdown ***/ // user_pref("browser.urlbar.maxRichResults", 0); /* 5012: disable location bar autofill * [1] https://support.mozilla.org/kb/address-bar-autocomplete-firefox#w_url-autocomplete ***/ // user_pref("browser.urlbar.autoFill", false); /* 5013: disable browsing and download history * [NOTE] We also clear history and downloads on exit (2811) * [SETTING] Privacy & Security>History>Custom Settings>Remember browsing and download history ***/ // user_pref("places.history.enabled", false); /* 5014: disable Windows jumplist [WINDOWS] ***/ // user_pref("browser.taskbar.lists.enabled", false); // user_pref("browser.taskbar.lists.frequent.enabled", false); // user_pref("browser.taskbar.lists.recent.enabled", false); // user_pref("browser.taskbar.lists.tasks.enabled", false); /* 5015: disable Windows taskbar preview [WINDOWS] ***/ // user_pref("browser.taskbar.previews.enable", false); // [DEFAULT: false] /* 5017: disable Form Autofill * If .supportedCountries includes your region (browser.search.region) and .supported * is "detect" (default), then the UI will show. Stored data is not secure, uses JSON * [SETTING] Privacy & Security>Forms and Autofill>Autofill addresses * [1] https://wiki.mozilla.org/Firefox/Features/Form_Autofill ***/ user_pref("extensions.formautofill.addresses.enabled", false); // [FF55+] user_pref("extensions.formautofill.creditCards.enabled", false); // [FF56+] /* 5018: limit events that can cause a pop-up ***/ user_pref("dom.popup_allowed_events", "click dblclick mousedown pointerdown"); /* 5019: disable page thumbnail collection ***/ // user_pref("browser.pagethumbnails.capturing_disabled", true); // [HIDDEN PREF] /*** [SECTION 5500]: OPTIONAL HARDENING Not recommended. Overriding these can cause breakage and performance issues, they are mostly fingerprintable, and the threat model is practically nonexistent ***/ user_pref("_user.js.parrot", "5500 syntax error: this is an ex-parrot!"); /* 5501: disable MathML (Mathematical Markup Language) [FF51+] * [1] https://cve.mitre.org/cgi-bin/cvekey.cgi?keyword=mathml ***/ // user_pref("mathml.disabled", true); // 1173199 /* 5502: disable in-content SVG (Scalable Vector Graphics) [FF53+] * [1] https://cve.mitre.org/cgi-bin/cvekey.cgi?keyword=firefox+svg ***/ // user_pref("svg.disabled", true); // 1216893 /* 5503: disable graphite * [1] https://cve.mitre.org/cgi-bin/cvekey.cgi?keyword=firefox+graphite * [2] https://en.wikipedia.org/wiki/Graphite_(SIL) ***/ // user_pref("gfx.font_rendering.graphite.enabled", false); /* 5504: disable asm.js [FF22+] * [1] http://asmjs.org/ * [2] https://cve.mitre.org/cgi-bin/cvekey.cgi?keyword=asm.js * [3] https://rh0dev.github.io/blog/2017/the-return-of-the-jit/ ***/ // user_pref("javascript.options.asmjs", false); /* 5505: disable Ion and baseline JIT to harden against JS exploits * [NOTE] When both Ion and JIT are disabled, and trustedprincipals * is enabled, then Ion can still be used by extensions (1599226) * [1] https://cve.mitre.org/cgi-bin/cvekey.cgi?keyword=firefox+jit * [2] https://microsoftedge.github.io/edgevr/posts/Super-Duper-Secure-Mode/ ***/ // user_pref("javascript.options.ion", false); // user_pref("javascript.options.baselinejit", false); // user_pref("javascript.options.jit_trustedprincipals", true); // [FF75+] [HIDDEN PREF] /* 5506: disable WebAssembly [FF52+] * Vulnerabilities [1] have increasingly been found, including those known and fixed * in native programs years ago [2]. WASM has powerful low-level access, making * certain attacks (brute-force) and vulnerabilities more possible * [STATS] ~0.2% of websites, about half of which are for crytopmining / malvertising [2][3] * [1] https://cve.mitre.org/cgi-bin/cvekey.cgi?keyword=wasm * [2] https://spectrum.ieee.org/tech-talk/telecom/security/more-worries-over-the-security-of-web-assembly * [3] https://www.zdnet.com/article/half-of-the-websites-using-webassembly-use-it-for-malicious-purposes ***/ // user_pref("javascript.options.wasm", false); /* 5507: disable rendering of SVG OpenType fonts ***/ // user_pref("gfx.font_rendering.opentype_svg.enabled", false); /*** [SECTION 6000]: DON'T TOUCH ***/ user_pref("_user.js.parrot", "6000 syntax error: the parrot's 'istory!"); /* 6001: enforce Firefox blocklist * [WHY] It includes updates for "revoked certificates" * [1] https://blog.mozilla.org/security/2015/03/03/revoking-intermediate-certificates-introducing-onecrl/ ***/ user_pref("extensions.blocklist.enabled", true); // [DEFAULT: true] /* 6002: enforce no referer spoofing * [WHY] Spoofing can affect CSRF (Cross-Site Request Forgery) protections ***/ user_pref("network.http.referer.spoofSource", false); // [DEFAULT: false] /* 6004: enforce a security delay on some confirmation dialogs such as install, open/save * [1] https://www.squarefree.com/2004/07/01/race-conditions-in-security-dialogs/ ***/ user_pref("security.dialog_enable_delay", 1000); // [DEFAULT: 1000] /* 6008: enforce no First Party Isolation [FF51+] * [WARNING] Replaced with network partitioning (FF85+) and TCP (2701), and enabling FPI * disables those. FPI is no longer maintained except at Tor Project for Tor Browser's config ***/ user_pref("privacy.firstparty.isolate", false); // [DEFAULT: false] /* 6009: enforce SmartBlock shims [FF81+] * In FF96+ these are listed in about:compat * [1] * https://blog.mozilla.org/security/2021/03/23/introducing-smartblock/ TODO: Do we really need this? ***/ user_pref("extensions.webcompat.enable_shims", true); // [DEFAULT: true] /* 6010: enforce no TLS 1.0/1.1 downgrades * [TEST] https://tls-v1-1.badssl.com:1010/ ***/ user_pref("security.tls.version.enable-deprecated", false); // [DEFAULT: false] /* 6011: enforce disabling of Web Compatibility Reporter [FF56+] * Web Compatibility Reporter adds a "Report Site Issue" button to send data to Mozilla * [WHY] To prevent wasting Mozilla's time with a custom setup ***/ user_pref("extensions.webcompat-reporter.enabled", false); // [DEFAULT: false] /* 6012: enforce Quarantined Domains [FF115+] * [WHY] https://support.mozilla.org/kb/quarantined-domains */ user_pref("extensions.quarantinedDomains.enabled", true); // [DEFAULT: true] /*** [SECTION 7000]: DON'T BOTHER ***/ user_pref("_user.js.parrot", "7000 syntax error: the parrot's pushing up daisies!"); /* 7001: disable APIs * Location-Aware Browsing, Full Screen * [WHY] The API state is easily fingerprintable. * Geo is behind a prompt (7002). Full screen requires user interaction ***/ user_pref("geo.enabled", false); user_pref("full-screen-api.enabled", false); /* 7002: set default permissions * Location, Camera, Microphone, Notifications [FF58+] Virtual Reality [FF73+] * 0=always ask (default), 1=allow, 2=block * [WHY] These are fingerprintable via Permissions API, except VR. Just add site * exceptions as allow/block for frequently visited/annoying sites: i.e. not global * [SETTING] to add site exceptions: Ctrl+I>Permissions> * [SETTING] to manage site exceptions: Options>Privacy & Security>Permissions>Settings ***/ // user_pref("permissions.default.geo", 0); // user_pref("permissions.default.camera", 0); // user_pref("permissions.default.microphone", 0); // user_pref("permissions.default.desktop-notification", 0); // user_pref("permissions.default.xr", 0); // Virtual Reality /* 7003: disable non-modern cipher suites [1] * [WHY] Passive fingerprinting. Minimal/non-existent threat of downgrade attacks * [1] https://browserleaks.com/ssl ***/ // user_pref("security.ssl3.ecdhe_ecdsa_aes_128_sha", false); // [DEFAULT: false FF109+] // user_pref("security.ssl3.ecdhe_ecdsa_aes_256_sha", false); // [DEFAULT: false FF109+] // user_pref("security.ssl3.ecdhe_rsa_aes_128_sha", false); // user_pref("security.ssl3.ecdhe_rsa_aes_256_sha", false); // user_pref("security.ssl3.rsa_aes_128_gcm_sha256", false); // no PFS // user_pref("security.ssl3.rsa_aes_256_gcm_sha384", false); // no PFS // user_pref("security.ssl3.rsa_aes_128_sha", false); // no PFS // user_pref("security.ssl3.rsa_aes_256_sha", false); // no PFS /* 7004: control TLS versions * [WHY] Passive fingerprinting and security ***/ // user_pref("security.tls.version.min", 3); // [DEFAULT: 3] // user_pref("security.tls.version.max", 4); /* 7005: disable SSL session IDs [FF36+] * [WHY] Passive fingerprinting and perf costs. These are session-only * and isolated with network partitioning (FF85+) and/or containers ***/ // user_pref("security.ssl.disable_session_identifiers", true); /* 7006: onions * [WHY] Firefox doesn't support hidden services. Use Tor Browser ***/ // user_pref("dom.securecontext.allowlist_onions", true); // [FF97+] 1382359/1744006 // user_pref("network.http.referer.hideOnionSource", true); // 1305144 /* 7007: referers * [WHY] Only cross-origin referers (1600s) need control ***/ // user_pref("network.http.sendRefererHeader", 2); // user_pref("network.http.referer.trimmingPolicy", 0); /* 7008: set the default Referrer Policy [FF59+] * 0=no-referer, 1=same-origin, 2=strict-origin-when-cross-origin, 3=no-referrer-when-downgrade * [WHY] Defaults are fine. They can be overridden by a site-controlled Referrer Policy ***/ // user_pref("network.http.referer.defaultPolicy", 2); // [DEFAULT: 2] // user_pref("network.http.referer.defaultPolicy.pbmode", 2); // [DEFAULT: 2] /* 7010: disable HTTP Alternative Services [FF37+] * [WHY] Already isolated with network partitioning (FF85+) ***/ // user_pref("network.http.altsvc.enabled", false); /* 7011: disable website control over browser right-click context menu * [WHY] Just use Shift-Right-Click ***/ // user_pref("dom.event.contextmenu.enabled", false); /* 7012: disable icon fonts (glyphs) and local fallback rendering * [WHY] Breakage, font fallback is equivalency, also RFP * [1] https://bugzilla.mozilla.org/789788 * [2] https://gitlab.torproject.org/legacy/trac/-/issues/8455 ***/ // user_pref("gfx.downloadable_fonts.enabled", false); // [FF41+] // user_pref("gfx.downloadable_fonts.fallback_delay", -1); /* 7013: disable Clipboard API * [WHY] Fingerprintable. Breakage. Cut/copy/paste require user * interaction, and paste is limited to focused editable fields ***/ // user_pref("dom.event.clipboardevents.enabled", false); /* 7014: disable System Add-on updates * [WHY] It can compromise security. System addons ship with prefs, use those ***/ // user_pref("extensions.systemAddon.update.enabled", false); // [FF62+] // user_pref("extensions.systemAddon.update.url", ""); // [FF44+] /* 7015: enable the DNT (Do Not Track) HTTP header * [WHY] DNT is enforced with Tracking Protection which is used in ETP Strict (2701) ***/ // user_pref("privacy.donottrackheader.enabled", true); /* 7016: customize ETP settings * [WHY] Arkenfox only supports strict (2701) which sets these at runtime ***/ // user_pref("network.cookie.cookieBehavior", 5); // [DEFAULT: 5 FF103+] // user_pref("network.http.referer.disallowCrossSiteRelaxingDefault", true); // user_pref("network.http.referer.disallowCrossSiteRelaxingDefault.top_navigation", true); // [FF100+] // user_pref("privacy.partition.network_state.ocsp_cache", true); // user_pref("privacy.query_stripping.enabled", true); // [FF101+] [ETP FF102+] // user_pref("privacy.trackingprotection.enabled", true); // user_pref("privacy.trackingprotection.socialtracking.enabled", true); // user_pref("privacy.trackingprotection.cryptomining.enabled", true); // [DEFAULT: true] // user_pref("privacy.trackingprotection.fingerprinting.enabled", true); // [DEFAULT: true] /* 7017: disable service workers * [WHY] Already isolated with TCP (2701) behind a pref (2710) ***/ user_pref("dom.serviceWorkers.enabled", false); /* 7018: disable Web Notifications * [WHY] Web Notifications are behind a prompt (7002) * [1] https://blog.mozilla.org/en/products/firefox/block-notification-requests/ ***/ user_pref("dom.webnotifications.enabled", false); // [FF22+] user_pref("dom.webnotifications.serviceworker.enabled", false); // [FF44+] /* 7019: disable Push Notifications [FF44+] * [WHY] Push requires subscription * [NOTE] To remove all subscriptions, reset "dom.push.userAgentID" * [1] https://support.mozilla.org/kb/push-notifications-firefox ***/ // user_pref("dom.push.enabled", false); /* 7020: disable WebRTC (Web Real-Time Communication) * [WHY] Firefox desktop uses mDNS hostname obfuscation and the private IP is never exposed until * required in TRUSTED scenarios; i.e. after you grant device (microphone or camera) access * [TEST] https://browserleaks.com/webrtc * [1] https://groups.google.com/g/discuss-webrtc/c/6stQXi72BEU/m/2FwZd24UAQAJ * [2] https://datatracker.ietf.org/doc/html/draft-ietf-mmusic-mdns-ice-candidates#section-3.1.1 ***/ // user_pref("media.peerconnection.enabled", false); /*** [SECTION 9000]: NON-PROJECT RELATED ***/ user_pref("_user.js.parrot", "9000 syntax error: the parrot's cashed in 'is chips!"); /* 9001: disable welcome notices ***/ user_pref("browser.startup.homepage_override.mstone", "ignore"); /* 9002: disable General>Browsing>Recommend extensions/features as you browse [FF67+] ***/ user_pref("browser.newtabpage.activity-stream.asrouter.userprefs.cfr.addons", false); user_pref("browser.newtabpage.activity-stream.asrouter.userprefs.cfr.features", false); /* 9003: disable What's New toolbar icon [FF69+] ***/ user_pref("browser.messaging-system.whatsNewPanel.enabled", false); /* 9004: disable search terms [FF110+] * [SETTING] Search>Search Bar>Use the address bar for search and navigation>Show search terms instead of URL... ***/ user_pref("browser.urlbar.showSearchTerms.enabled", false); // other user_pref("xpinstall.signatures.required", false); user_pref("xpinstall.whitelist.required", false); // org-protocol user_pref("network.protocol-handler.app.org-protocol", "emacsclient -n"); user_pref("network.protocol-handler.expose.org-protocol", false); user_pref("network.protocol-handler.external.org-protocol", true); user_pref("devtools.editor.keymap", "emacs"); /* END: internal custom pref to test for syntax errors ***/ user_pref("_user.js.parrot", "SUCCESS: No no he's not dead, he's, he's restin'!");