Download Tor Browser 5.0.1

Version 5.0 of Tor Browser was released last week and an update has already been released. Tor stands for The Onion Router and is a network that can be used to surf the Internet fairly anonymously. All users’ tcp traffic is routed through various Tor routers, after which it is virtually impossible for the receiver to trace who the original sender was. This information is still present within the Tor network, so that answers, of course also via the system of routers, eventually arrive at the right place.

New in version 5.0, which is based on Firefox’s Extended Support Release version 38.2, is that updates can be retrieved automatically in the background.

Tor Browser 5.0.1 has been released

This release fixes a crash bug that caused Tor Browser to crash on certain sites (in particular, Google Maps and Tumblr). The crash bug was a NULL pointer dereference while handling blob URIs. The crash was not exploitable. Here is the complete changelog since 5.0:

All Platforms

• Bug 16771: Fix crash on some websites due to blob URIs

Tor Browser 5.0 has been released

This release features important security updates to firefox. Note that the recent PDF.js exploit did not affect 4.5 users, but they should upgrade to this release immediately because numerous other potential security issues were fixed by Mozilla in this release. (Incidentally: Users who are using the 5.0-alpha series are vulnerable to the PDF.js exploit, but not if they were using the ‘High’ security level. Regardless, we are also upgrading 5.0-alpha users to 5.5a1 today to fix the issue as well).

This release also brings us up to date with Firefox 38-ESR, which should mean improved support for HTML5 video on Youtube, as well as a host of other improvements. Controversial and hard-to-audit binary components related to EME DRM were disabled, however.

The release also features new privacy enhancements. In particular, more identifier sources that appeared in Firefox 38 (or were otherwise disabled previously) are now isolated to the first party (URL bar) domain. This release also contains defenses from the 5.0-alpha series for keystroke (typing) fingerprinting and some instances of performance/timing fingerprinting.

Regrettably, our new defenses for font and keyboard layout fingerprinting did not stabilize in time for this release. Users who are interested in helping us improve them should try out 5.5a1.

This release also will reset the permanent NoScript whitelist, due to an issue where previous NoScript updates had added certain domains to the whitelist during upgrade. The whitelist is reset to the default for all users as a result, and future updates to the whitelist by NoScript have been disabled.

Starting with this release, Tor Browser will now also download and apply upgrades in the background, to ensure that users upgrade quicker and with less interaction. This behavior is governed by the about:config pref app.update.auto, but we do not recommend disabling it unless you really know what you’re doing. Here is the complete changelog since 4.5.3:

All Platforms

• Update Firefox to 38.2.0esr
• Update OpenSSL to 1.0.1p
• Update HTTPS Everywhere to 5.0.7
• Update NoScript to 2.6.9.34
• Update meek to 0.20
• Update Tor to 0.2.6.10 with patches:
  • Bug 16674: Allow FQDNs ending with a single ‘.’ in our SOCKS host name checks.
  • Bug 16430: Allow DNS names with _ characters in them (fixes nytimes.com)
  • Bug 15482: Don’t allow circuits to change while a site is in use
• Update Torbutton to 1.9.3.2
  • Bug 16731: TBB 5.0 a3/a4 fails to download a file on right click
  • Bug 16730: Reset NoScript whitelist on upgrade
  • Bug 16722: Prevent “Tiles” feature from being enabled after upgrade
  • Bug 16488: Remove “Sign in to Sync” from the browser menu (fixup)
  • Bug 16268: Show Tor Browser logo on About page
  • Bug 16639: Check for Updates menu item can cause update download failure
  • Bug 15781: Remove the sessionstore filter
  • Bug 15656: Sync privacy.resistFingerprinting with Torbutton pref
  • Bug 16427: Use internal update URL to block updates (instead of 127.0.0.1)
  • Bug 16200: Update Cache API usage and prefs for FF38
  • Bug 16357: Use Mozilla API to wipe permissions db
  • Bug 14429: Make sure the automatic resizing is disabled
  • Translation updates
• Update Tor Launcher to 0.2.7.7
  • Bug 16428: Use internal update URL to block updates (instead of 127.0.0.1)
  • Bug 15145: Visually distinguish “proxy” and “bridge” screens.
  • Translation updates
• Bug 16730: Prevent NoScript from updating the default whitelist
• Bug 16715: Use ThreadsafeIsCallerChrome() instead of IsCallerChrome()
• Bug 16572: Verify cache isolation for XMLHttpRequests in Web Workers
• Bug 16884: Prefer IPv6 when supported by the current Tor exit
• Bug 16488: Remove “Sign in to Sync” from the browser menu
• Bug 16662: Enable network.http.spdy.* prefs in meek-http-helper
• Bug 15703: Isolate mediasource URIs and media streams to first party
• Bug 16429+16416: Isolate blob URIs to first party
• Bug 16632: Turn on the background updater and restart prompting
• Bug 16528: Prevent indexedDB Modernizr site breakage on Twitter and elsewhere
• Bug 16523: Fix in-browser JavaScript debugger
• Bug 16236: Windows updater: avoid writing to the registry
• Bug 16625: Fully disable network connection prediction
• Bug 16495: Fix SVG crash when security level is set to “High”
• Bug 13247: Fix meek profile error after bowser restarts
• Bug 16005: Relax WebGL minimal mode
• Bug 16300: Isolate Broadcast Channels to first party
• Bug 16439: Remove Roku screencasting code
• Bug 16285: Disabling EME bits
• Bug 16206: Enforce certificate pinning
• Bug 15910: Disable Gecko Media Plugins for now
• Bug 13670: Isolate OCSP requests by first party domain
• Bug 16448: Isolate favicon requests by first party
• Bug 7561: Disable FTP request caching
• Bug 6503: Fix single-word URL bar searching
• Bug 15526: ES6 page crashes Tor Browser
• Bug 16254: Disable GeoIP-based search results.
• Bug 16222: Disable WebIDE to prevent remote debugging and addon downloads.
• Bug 13024: Disable DOM Resource Timing API
• Bug 16340: Disable User Timing API
• Bug 14952: Disable HTTP/2
• Bug 1517: Reduce precision of time for Javascript
• Bug 13670: Ensure OCSP & favicons respect URL bar domain isolation
• Bug 16311: Fix navigation timing in ESR 38

Windows

• Bug 16014: Staged update fails if meek is enabled
• Bug 16269: repeated add-on compatibility check after update (meek enabled)

Mac OS

• Use OSX 10.7 SDK
• Bug 16253: Tor Browser menu on OS X is broken with ESR 38
• Bug 15773: Enable ICU on OS X

Build System

• Bug 16351: Upgrade our toolchain to use GCC 5.1
• Bug 15772 and child tickets: Update build system for Firefox 38
• Bugs 15921+15922: Fix build errors during Mozilla Tryserver builds
• Bug 15864: rename sha256sums.txt to sha256sums-unsigned-build.txt