ODBC can be accessed in SSIS using ADO.NET connection manager.

To create ADO.NET connection for ODBC, Add new ADO.NET connection manager, go to Provider drop down, select ODBC Data Provider from drop down list.

This ODBC connection can be accessed using DataReader Source in Data Flow Task.

Note that ADO.NET connection manager does not support varchar data type. So automatically columns with varchar data type will be converted to nvarchar data type. In data flow task nvarchar data type can be converted back to varchar.