Changes in synapse v0.18.3 (2016-11-08)
SECURITY UPDATE
Explicitly require authentication when using LDAP3. This is the default on
versions of ldap3 above 1.0, but some distributions will package an older
version.
If you are using LDAP3 login and have a version of ldap3 older than 1.0 it
is CRITICAL to updgrade.