Critical Security Update: Synapse 0.33.3.1

Hi All,

As referenced in yesterday's pre-disclosure, today we are releasing Synapse 0.33.3.1 as a critical security update.

We have patched two security vulnerabilities we identified whilst working on the upcoming r0 spec release for the Server-Server API (see details below). We do not believe either have been exploited in the wild, but strongly recommend everybody running a federated Synapse upgrades immediately.

As always you can get the new update here or from any of the sources mentioned at https://github.com/matrix-org/synapse/

Many thanks for your patience and understanding; with fixes like this we are moving ever closer to Synapse reaching a 1.0 Thanks also to the package maintainers who have coordinated with us to ensure distro packages are available for a speedy upgrade!

Note, for anyone running Debian Jessie, we have prepared a 0.33.2.1 deb (as 0.33.3 dropped support for Jessie).

Synapse 0.33.3.1 (2018-09-06)

SECURITY FIXES

• Fix an issue where event signatures were not always correctly validated (#3796)
• Fix an issue where server_acls could be circumvented for incoming events (#3796)

Internal Changes

• Unignore synctl in .dockerignore to fix docker builds (#3802)