PostgreSQL 7.3 before 7.3.13, 7.4 before 7.4.16, 8.0 before 8.0.11, 8.1 before 8.1.7, and 8.2 before 8.2.2 allows attackers to disable certain checks for the data types of SQL function arguments, which allows remote authenticated users to cause a denial of service (server crash) and possibly access database content.