Race condition in the (1) CREATE INDEX and (2) unspecified ALTER TABLE commands in PostgreSQL before 8.4.20, 9.0.x before 9.0.16, 9.1.x before 9.1.12, 9.2.x before 9.2.7, and 9.3.x before 9.3.3 allows remote authenticated users to create an unauthorized index or read portions of unauthorized tables by creating or deleting a table with the same name during the timing window.
The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.