A weakness was found in postgresql-jdbc before version 42.2.5. It was possible to provide an SSL Factory and not check the host name if a host name verifier was not provided to the driver. This could lead to a condition where a man-in-the-middle attacker could masquerade as a trusted server by providing a certificate for the wrong host, as long as it was signed by a trusted CA.

pgjdbc is an open source postgresql JDBC Driver. From 42.7.4 and until 42.7.7, when the PostgreSQL JDBC driver is configured with channel binding set to required (default value is prefer), the driver would incorrectly allow connections to proceed with authentication methods that do not support channel binding (such as password, MD5, GSS, or SSPI authentication). This could allow a man-in-the-middle attacker to intercept connections that users believed were protected by channel binding requirements. This vulnerability is fixed in 42.7.7.