PostgreSQL 9.2.x before 9.2.3, 9.1.x before 9.1.8, 9.0.x before 9.0.12, 8.4.x before 8.4.16, and 8.3.x before 8.3.23 does not properly declare the enum_recv function in backend/utils/adt/enum.c, which causes it to be invoked with incorrect arguments and allows remote authenticated users to cause a denial of service (server crash) or read sensitive process memory via a crafted SQL command, which triggers an array index error and an out-of-bounds read.