pgjdbc Client Allows Fallback to Insecure Authentication Despite channelBinding=require Configuration

Impact

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.

Patches

TBD

Workarounds

Configure sslMode=verify-full to prevent MITM attacks.

References

• https://www.postgresql.org/docs/current/sasl-authentication.html#SASL-SCRAM-SHA-256
• https://datatracker.ietf.org/doc/html/rfc7677
• https://datatracker.ietf.org/doc/html/rfc5802