The core server component in PostgreSQL 8.4 before 8.4.1, 8.3 before 8.3.8, and 8.2 before 8.2.14 allows remote authenticated users to cause a denial of service (backend shutdown) by "re-LOAD-ing" libraries from a certain plugins directory.

PostgreSQL before 8.3.7, 8.2.13, 8.1.17, 8.0.21, and 7.4.25 allows remote authenticated users to cause a denial of service (stack consumption and crash) by triggering a failure in the conversion of a localized error message to a client-specified encoding, as demonstrated using mismatched encoding conversion requests.

PostgreSQL 8.2 before 8.2.6, 8.1 before 8.1.11, 8.0 before 8.0.15, 7.4 before 7.4.19, and 7.3 before 7.3.21 uses superuser privileges instead of table owner privileges for (1) VACUUM and (2) ANALYZE operations within index functions, and supports (3) SET ROLE and (4) SET SESSION AUTHORIZATION within index functions, which allows remote authenticated users to gain privileges.

The query planner in PostgreSQL before 8.0.11, 8.1 before 8.1.7, and 8.2 before 8.2.2 does not verify that a table is compatible with a "previously made query plan," which allows remote authenticated users to cause a denial of service (server crash) and possibly access database content via an "ALTER COLUMN TYPE" SQL statement, which can be leveraged to read arbitrary memory from the server.