Access to external executables must be disabled or restricted.

From IBM DB2 V10.5 LUW Security Technical Implementation Guide

Associated with: CCI-000381

SV-89157r1_rule Access to external executables must be disabled or restricted.

Vulnerability discussion

Information systems are capable of providing a wide variety of functions and services. Some of the functions and services, provided by default, may not be necessary to support essential organizational operations (e.g., key missions, functions). It is detrimental for applications to provide, or install by default, functionality exceeding requirements or mission objectives. Applications must adhere to the principles of least functionality by providing only essential capabilities.DBMSs may spawn additional external processes to execute procedures that are defined in the DBMS but stored in external host files (external procedures). The spawned process used to execute the external procedure may operate within a different OS security context than the DBMS and provide unauthorized access to the host system.

Check content

Use the following SQL Query to find external routines: DB2> SELECT ROUTINENAME FROM SYSCAT.ROUTINES WHERE ORIGIN='E' Use the following command to find out which user has privileges to run the external routines found with last query. DB2> SELECT GRANTEE FROM SYSCAT.ROUTINEAUTH If non-essential routines exist outside the database, this is a finding. If non-authorized users have privileges on external routines, this is a finding.

Fix text

Drop the external routines if these are non-essential for mission objective. DB2> DROP FUNCTION Revoke execute privileges from non-authorized users on external routines. DB2> REVOKE EXECUTE ON FUNCTION FROM Note: Select the following link for the knowledgebase information on the DROP statement: http://www.ibm.com/support/knowledgecenter/SSEPGG_10.5.0/com.ibm.db2.luw.sql.ref.doc/doc/r0000945.html?cp=SSEPGG_10.5.0%2F2-12-7-129&lang=en

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