31.9. Security
A user able to modify the schema of subscriber-side tables can execute
arbitrary code as the role which owns any subscription which modifies those tables. Limit ownership
and
TRIGGER
privilege on such tables to trusted roles.
Moreover, if untrusted users can create tables, use only
publications that list tables explicitly. That is to say, create a
subscription
FOR ALL TABLES
or
FOR TABLES IN SCHEMA
only when superusers trust
every user permitted to create a non-temp table on the publisher or the
subscriber.
The role used for the replication connection must have
the
REPLICATION
attribute (or be a superuser). If the
role lacks
SUPERUSER
and
BYPASSRLS
,
publisher row security policies can execute. If the role does not trust
all table owners, include
options=-crow_security=off
in
the connection string; if a table owner then adds a row security policy,
that setting will cause replication to halt rather than execute the policy.
Access for the role must be configured in
pg_hba.conf
and it must have the
LOGIN
attribute.
In order to be able to copy the initial table data, the role used for the
replication connection must have the
SELECT
privilege on
a published table (or be a superuser).
To create a publication, the user must have the
CREATE
privilege in the database.
To add tables to a publication, the user must have ownership rights on the table. To add all tables in schema to a publication, the user must be a superuser. To create a publication that publishes all tables or all tables in schema automatically, the user must be a superuser.
To create a subscription, the user must be a superuser.
The subscription apply process will run in the local database with the privileges of the subscription owner.
On the publisher, privileges are only checked once at the start of a replication connection and are not re-checked as each change record is read.
On the subscriber, the subscription owner's privileges are re-checked for each transaction when applied. If a worker is in the process of applying a transaction when the ownership of the subscription is changed by a concurrent transaction, the application of the current transaction will continue under the old owner's privileges.