Luke Grimes has recently joined a multinational company as a cloud security engineer. The company has been using the AWS cloud. He would like to reduce the risk of man-in-the-middle attacks in all Redshift clusters. Which of the following parameters should Grimes enable to reduce the risk of man-in-the-middle attacks in all Redshift clusters?

To mitigate man-in-the-middle (MITM) attacks, data in transit must be encrypted. In Amazon Redshift, the requiressl parameter, when set to true in a parameter group, enforces that all client connections to the cluster must use Secure Sockets Layer (SSL) or Transport Layer Security (TLS) encryption. If a client attempts to connect without SSL, the connection is rejected. This ensures that all data exchanged between the client and the Redshift cluster is encrypted, preventing eavesdropping and MITM attacks. This is the direct and primary mechanism for enforcing SSL on all connections.

A. wlmssl is not a valid Amazon Redshift parameter for enforcing SSL connections. Workload Management (WLM) is used for managing query priorities.
B. enableuserssl is not a standard Amazon Redshift parameter. SSL is configured at the cluster level via parameter groups, not on a per-user basis with this syntax.
D. fipsssl is not a valid parameter. While Redshift can be configured for FIPS 140-2 compliance, this is not the parameter used to enforce SSL for all connections.

1. AWS. (n.d.). Amazon Redshift Database Developer Guide. Section "Configuring security options for connections". Retrieved from https://docs.aws.amazon.com/redshift/latest/mgmt/connecting-ssl-support.html. The documentation states, "To enforce SSL connections, set the requiressl parameter to true in the parameter group that is associated with the cluster."

2. AWS. (n.d.). Amazon Redshift Management Guide. Section "Amazon Redshift parameter groups". Retrieved from https://docs.aws.amazon.com/redshift/latest/mgmt/working-with-parameter-groups.html. This guide details how to modify cluster parameters, including requiressl, to change database behavior.

3. AWS. (n.d.). Amazon Redshift Database Developer Guide. Section "Modifiable cluster parameters". Retrieved from https://docs.aws.amazon.com/redshift/latest/dg/rmodifyclusterparameters.html. This page lists requiressl as a modifiable parameter with a boolean type that "Requires that incoming connections be SSL-encrypted."