PostgreSQL before 9.0.19, 9.1.x before 9.1.15, 9.2.x before 9.2.10, 9.3.x before 9.3.6, and 9.4.x before 9.4.1 does not properly handle errors while reading a protocol message, which allows remote attackers to conduct SQL injection attacks via crafted binary data in a parameter and causing an error, which triggers the loss of synchronization and part of the protocol message to be treated as a new message, as demonstrated by causing a timeout or query cancellation.