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project:spyzilla

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Spyzilla

Mozilla products by default send some information to NSA. This guide will show you how to change these settings to other secret service of your choice or how to turn them off completely.

See also list of other applications that do not respect privacy.

Client certificates

Check Advanced → Certificates → Ask me every time, we really don't want to authenticate to the remote server automatically! Exploited in the wild!

Firefox

This applies to Firefox <57. We have downloaded Firefox 57, started it, left it for ~30 minutes and were amazed:

  • Run with parameter -P. Select “Start offline”
  • Visit Preferences. In “Security”, turn off “Block reported attack sites” and “Block reported web forgeries”
  • Uncheck Advanced → Updates
  • Uncheck Advanced → Certificates → Validation → OCSP (of course this disables fetching certificate revocation info - be sure you know what are you doing)
  • Visit about:config. Set extensions.blocklist.enabled = false.
  • Search for “http”. Change all URLs to nsalitomerice.cz, localhost or other secret service of your choice.
  • Unfortunately, Firefox will still download favicons from Google, Yahoo and Mibbit (incl. cookies) when browsing Preferences in a certain way. Bugreport pending.
  • Since FF 32, on Windows, hashes of certain downloaded files are sent to Google. This can be disabled by the aforementioned settings. 1, 2
  • If you want to test this with an intercepting proxy, make sure you have security.cert_pinning.enforcement_level 0 or 1
  • Disable automatic resolving of local names and URL-like patters: set browser.fixup.alternate.enabled and keyword.enabled to false. PT
  • media.peerconnection.enabled: false (enumhosts, mirror)

  • Every time you open new window, Firefox posts your system information to Mozilla, e.g. this one. This can be avoided by aforementioned URL settings or by setting homepage to about:blank.
  • Yes, we have API for manipulating browser history. I have no idea if something interesting can be done with it. See browser.history.allow* in about:config.
    • Setting this to False breaks webpages, known problems are with zbozi.cz and mapy.cz.
  • Files in local filesystem can read files in current directory and post them to a remote server.
    • Download this image to your home directory and open it in Firefox.
  • HSTS settings cannot be overriden (the decision can be hand-deleted from SiteSecurityServiceState.txt when Firefox is not running (otherwise the file is immediately overwritten), however, if the page sends further broken HSTS headers, subsequent requests will fail anyway). This is in compliance with RFC 6797, section 12.1. NSA Litoměřice believes that this is one of RFCs that are badly designed and should be ignored (the other being e.g. RFC 826, which we describe here)
    • You can override it by adding test.currentTimeOffsetSeconds (integer) = 11491200
    • And in Chrome, you can override it by typing “badidea” on the error page
    • Neither it seems to be possible to override revoked certificate
  • The webpage can detect that element inspector is opened. This should be possible to disable too…
  • Recommended: network.IDN_show_punycode = true (more info)
  • Firefox 52 ESR downloads browser.safebrowsing.provider.mozilla.gethashURL even if safe browsing is turned off in Preferences

See: Firefox hardening

See also this guide. I have downloaded it from an onion service and put it here for those who don't have access to the darknet.

To be investigated:

Thunderbird

New Account setup wizard sends your e-mail domain to Mozilla. To add an account without this feature, select File → Offline → Work offline.

Firefox for Android

Checks for updates even when the main app is not running. Same as described here.

This update checking does not respect network.proxy.http settings, but connect straight to the network, i.e., a standard intercepting proxy setup won't see it, it won't go through Tor etc.

project/spyzilla.1518881690.txt.gz · Last modified: 2018/02/17 15:34 by jenda