Privilege Dropping / Lowering Errors

Summary

Late privilege drop in `REFRESH MATERIALIZED VIEW CONCURRENTLY` in PostgreSQL allows an object creator to execute arbitrary SQL functions as the command issuer. The command intends to run SQL functions as the owner of the materialized view, enabling safe refresh of untrusted materialized views. The victim is a superuser or member of one of the attacker's roles. The attack requires luring the victim into running `REFRESH MATERIALIZED VIEW CONCURRENTLY` on the attacker's materialized view. This issue affects PostgreSQL versions prior to 12.18, 13.x prior to 13.14, 14.x prior to 14.11, 15.x prior to 15.6 and 16.x prior to 16.2.