Impact

SQL injection can occur if an attacker can cause a single query or bind message to exceed 4 GB in size. An integer overflow in the calculated message size can cause the one large message to be sent as multiple messages under the attacker's control.

Patches

The problem is resolved in v4.18.2 and v5.5.4.

Workarounds

Reject user input large enough to cause a single query or bind message to exceed 4 GB in size.

The DataRow.Decode function fails to properly validate field lengths. A malicious or compromised PostgreSQL server can send a DataRow message with a negative field length, causing a slice bounds out of range panic.