CloudBerry Explorer has been updated with support for AWS Security Token Service.
Support for AWS Security Token Service
CloudBerry Explorer 5.5.1 now features the ability to authenticate via AWS Security Token Service (STS). The AWS STS is a web service that enables you to request temporary, limited-privilege credentials for AWS IAM users or for users that you authenticate (federated users). Feel free to read Amazon's documentation to lean more about the service.
You can leverage the STS authentication in CloudBerry Explorer when adding a new S3 account. Simply click Advanced when entering credentials, specify the session token, and you should be good to go.
CloudBerry Explorer 5.5.1