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Reviewing Hive UDFs for security risks

Verify that a Hive function does not use restricted classes or contain malicious code before you grant the SELECT privilege to a user.

Before you grant the SELECT privilege on a Hive function, you must verify that the function is secure. This process helps prevent the execution of unauthorized code and ensures that only trusted UDFs are accessible to users.
You must have administrative access to the Ranger UI and the ability to run commands in Beeline or the Hue Hive editor.
  1. Run the following command in Beeline or the Hue Hive editor to check the function details: 
    DESCRIBE FUNCTION EXTENDED <db_name>.<udf_name>;
  2. Review the Function class property in the output to identify the underlying Java class.
  3. Verify that the UDF does not use restricted classes.
    Confirm that the Function class is not one of the following elements:
    • org.apache.hadoop.hive.ql.udf.generic.GenericUDFReflect
    • org.apache.hadoop.hive.ql.udf.generic.GenericUDFReflect2
    • org.apache.hadoop.hive.ql.udf.generic.GenericUDFInFile
  4. Conduct an internal code review of the custom UDF.
    Ensure the code does not perform the following actions:
    • Execute external scripts
    • Use unauthorized reflection or custom code execution
After verifying that the function class is safe and the code is trusted, you can proceed with granting the SELECT privilege in Ranger.