Snowflake JDBC Driver auto-configuration account validation permits credential redirection

Improper input validation of the auto-configuration account identifier in Snowflake JDBC Driver versions 4.2.0 through 4.3.3 allowed a credential-bearing login request to be redirected to an attacker-selected HTTPS endpoint. An attacker able to control the account value could cause the driver to transmit a reusable login credential to a host of their choosing and replay it to obtain the privileges granted to that credential. Successful exploitation requires an application using jdbc:snowflake:auto with a connections.toml section that omits an explicit host and a lower-trust principal able to set the account value; ordinary JDBC URLs are unaffected. The fix is available in Snowflake JDBC Driver version 4.3.4. Users must manually upgrade.