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Firefox bullshit removal via about:config

Firefox bullshit removal

Due to the incessant swarm of complete and utter nonsense that has been forcing its way into Firefox over time, I've decided to start collecting my personal list of “must-have” about:config tweaks required to turn Firefox into a functional brower.

NOTE: Unfortunately this is somewhat out of date. The comments link to some resources that may be more up-to-date. Patches welcome.

WebSockets

These can be used for nefarious purposes and to bypass access restrictions.

network.websocket.enabled=false

JavaScript spy vectors

These can be used for fingerprinting or data collection about the host system.

dom.event.clipboardevents.enabled=false
dom.battery.enabled=false
browser.send_pings=false
webgl.disabled=true

Pocket integration

This is a proprietary tie-in service that is a risk to your privacy.

  1. Drag the “pocket” icon off your toolbar. This step is important.
  2. browser.pocket.enabled=false

WebRTC

This is an inter-browser communication standard that is a very significant risk to your privacy and can be used to break out of VPN tunnels, proxies and unmask local users.

media.peerconnection.enabled=false
loop.enabled=false

DRM

This is a significant breach of your personal freedom and security.

media.eme.enabled=false
media.gmp-eme-adobe.enabled=false

GeoLocation / Beacon

These can be used for tracking and fingerprinting services and are harmful to your privacy

browser.beacen.enabled=false
geo.enabled=false
geo.wifi.logging.enabled=false
geo.wifi.uri=""

Safe browsing

This requires Firefox to communicate with a third party, Google by default, and also sends them metadata about your downloads.

browser.safebrowsing.enabled=false
browser.safebrowsing.downloads.enabled=false
browser.safebrowsing.malware.enabled=false

Social media integration

This anti-feature lets social media platforms integrate directly into your browser

social.directories=""
social.whitelist=""
social.manifest.facebook=""
social.remote-install.enabled=false
social.toast-notifications.enabled=false

Device tracking/statistics

These can be used to fingerprint your system and track you.

device.sensors.enabled=false
camera.control.face_detection.enabled=false
camera.control.autofocus_moving_callback.enabled=false

Tracking protection

This makes Firefox block known tracking domains by default.

privacy.trackingprotection.enabled=true

DNT Header

This makes Firefox include a DNT (“do not track”) header in its request. Theoretically, this would opt-out of tracking services for some services, but unfortunately it makes your fingerprint much more trackable, as this header is not too common. Enable if it you want, but it's probably best to leave it off to prevent tracking.

privacy.donottrackheader.enabled=true

Stat tracking / telemetry

These are used by Mozilla to spy on you, and are as such a significant risk to privacy.

datareporting.healthreport.service.enabled=false
datareporting.healthreport.uploadEnabled=false
toolkit.telemetry.enabled=false

Link pre-fetching

These will make Firefox connect with arbitrary links on a page by the simple act of hovering over them, without your explicit permission.

network.http.speculative-parallel-limit=0

Cryptography hardening

This disables algorithms that are known to be weak or broken, and prevents most common attack vectors. Be warned that this may break some older websites that are not compatible with modern protocols.

General settings

security.tls.unrestricted_rc4_fallback=false
security.tls.insecure_fallback_hosts.use_static_list=false
security.tls.version.min=1
security.ssl.require_safe_negotiation=true
security.ssl.treat_unsafe_negotiation_as_broken=true
security.ssl3.rsa_seed_sha=true
security.OCSP.enabled=1
security.OCSP.require=true

Disable unnecessary protocols

This disables older protocols that are known to be weak or entirely broken (3DES, RC4 and MD5).

security.ssl3.rsa_rc4_128_sha=false
security.ssl3.rsa_rc4_128_md5=false
security.ssl3.rsa_des_ede3_sha=false
security.ssl3.ecdhe_ecdsa_rc4_128_sha=false
security.ssl3.ecdhe_rsa_rc4_128_sha=false

Perfect forward secrecy

If you (additionally) want to force the usage of PFS, the only enabled ciphers should be of the ecdhe/dhe variants. Might break lots of stuff.

security.ssl3.rsa_aes_256_sha=false

Force TLS 1.2

This disables TLS 1.0 and TLS 1.1 completely, which increases security as these older protocols may be used as attack vectors. (Note that TLS technically contains a mechanism for preventing protocol degradation attacks, but it requires participation from both the client and the server - which is not a guarantee in practice)

security.tls.version.min=3

Recommended addons (bonus)

In addition to the above settings, I personally recommend the usage of at least the following addons:

  • HTTPS Everywhere: Prefer HTTPS over HTTP even for sites that do not force HSTS.
  • μBlock₀: Block access to all known ads, malware domains, badware, and other malicious scripts and domains.
  • uMatrix or NoScript+RequestPolicy: Block scripts, images, CSS, objects and other (possibly external) requests by default, using a whitelist to selectively allow them. This is highly recommended as they all pose significant threats to security and privacy.
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