Hello!
There's a new alpha Tor release! Because it's an alpha, you should
only run it if you're ready to find more bugs than usual, and report
them on trac.torproject.org.
The source code is available from the usual place on
www.torproject.org; if you build Tor from source, why not give it a
try? And if you don't build Tor from source, packages should be ready
over the coming days, with a Tor Browser alpha release likely in the
next few weeks.
This release fixes TROVE-2019-001, a possible security bug involving
the KIST cell scheduler code in versions 0.3.2.1-alpha and later. We
are not certain that it is possible to exploit this bug in the wild,
but to be careful, we recommend that all affected users upgrade. The
potential impact is a remote denial-of-service attack against clients
or relays.
Here's what's new:
Changes in version 0.4.0.2-alpha - 2019-02-21
Tor 0.4.0.2-alpha is the second alpha in its series; it fixes several
bugs from earlier versions, including several that had broken
backward compatibility.
It also includes a fix for a medium-severity security bug affecting Tor
0.3.2.1-alpha and later. All Tor instances running an affected release
should upgrade to 0.3.3.12, 0.3.4.11, 0.3.5.8, or 0.4.0.2-alpha.
o Major bugfixes (cell scheduler, KIST, security):
- Make KIST consider the outbuf length when computing what it can
put in the outbuf. Previously, KIST acted as though the outbuf
were empty, which could lead to the outbuf becoming too full. It
is possible that an attacker could exploit this bug to cause a Tor
client or relay to run out of memory and crash. Fixes bug 29168;
bugfix on 0.3.2.1-alpha. This issue is also being tracked as
TROVE-2019-001 and CVE-2019-8955.
o Major bugfixes (networking):
- Gracefully handle empty username/password fields in SOCKS5
username/password auth messsage and allow SOCKS5 handshake to
continue. Previously, we had rejected these handshakes, breaking
certain applications. Fixes bug 29175; bugfix on 0.3.5.1-alpha.
o Major bugfixes (windows, startup):
- When reading a consensus file from disk, detect whether it was
written in text mode, and re-read it in text mode if so. Always
write consensus files in binary mode so that we can map them into
memory later. Previously, we had written in text mode, which
confused us when we tried to map the file on windows. Fixes bug
28614; bugfix on 0.4.0.1-alpha.
o Minor features (compilation):
- Compile correctly when OpenSSL is built with engine support
disabled, or with deprecated APIs disabled. Closes ticket 29026.
Patches from "Mangix".
o Minor features (developer tooling):
- Check that bugfix versions in changes files look like Tor versions
from the versions spec. Warn when bugfixes claim to be on a future
release. Closes ticket 27761.
- Provide a git pre-commit hook that disallows commiting if we have
any failures in our code and changelog formatting checks. It is
now available in scripts/maint/pre-commit.git-hook. Implements
feature 28976.
o Minor features (directory authority):
- When a directory authority is using a bandwidth file to obtain
bandwidth values, include the digest of that file in the vote.
Closes ticket 26698.
o Minor features (geoip):
- Update geoip and geoip6 to the February 5 2019 Maxmind GeoLite2
Country database. Closes ticket 29478.
o Minor features (testing):
- Treat all unexpected ERR and BUG messages as test failures. Closes
ticket 28668.
o Minor bugfixes (build, compatibility, rust):
- Update Cargo.lock file to match the version made by the latest
version of Rust, so that "make distcheck" will pass again. Fixes
bug 29244; bugfix on 0.3.3.4-alpha.
o Minor bugfixes (compilation):
- Fix compilation warnings in test_circuitpadding.c. Fixes bug
29169; bugfix on 0.4.0.1-alpha.
- Silence a compiler warning in test-memwipe.c on OpenBSD. Fixes bug
29145; bugfix on 0.2.9.3-alpha. Patch from Kris Katterjohn.
o Minor bugfixes (documentation):
- Describe the contents of the v3 onion service client authorization
files correctly: They hold public keys, not private keys. Fixes
bug 28979; bugfix on 0.3.5.1-alpha. Spotted by "Felixix".
o Minor bugfixes (linux seccomp sandbox):
- Fix startup crash when experimental sandbox support is enabled.
Fixes bug 29150; bugfix on 0.4.0.1-alpha. Patch by Peter Gerber.
o Minor bugfixes (logging):
- Avoid logging that we are relaxing a circuit timeout when that
timeout is fixed. Fixes bug 28698; bugfix on 0.2.4.7-alpha.
- Log more information at "warning" level when unable to read a
private key; log more information at "info" level when unable to
read a public key. We had warnings here before, but they were lost
during our NSS work. Fixes bug 29042;
