V-214095

Discussion

Failed attempts to change the permissions, privileges, and roles granted to users and roles must be tracked. Without an audit trail, unauthorized attempts to elevate or restrict privileges could go undetected. In an SQL environment, deleting permissions is typically done via the REVOKE command. To aid in diagnosis, it is necessary to keep track of failed attempts in addition to the successful ones.

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Note: The following instructions use the PGDATA environment variable. See supplementary content APPENDIX-F for instructions on configuring PGDATA. 

First, as the database administrator (shown here as "postgres"), create the roles joe and bob with LOGIN by running the following SQL: 

$ sudo su - postgres 
$ psql -c "CREATE ROLE joe LOGIN" 
$ psql -c "CREATE ROLE bob LOGIN" 

Next, set current role to bob and attempt to alter the role joe: 

$ psql -c "SET ROLE bob; ALTER ROLE joe NOLOGIN;" 

Now, as the database administrator (shown here as "postgres"), verify the denials are logged: 

$ sudo su - postgres 
$ cat ${PGDATA?}/pg_log/<latest_log> 
< 2016-03-17 11:28:10.004 EDT bob 56eacd05.cda postgres: >ERROR: permission denied to alter role 
< 2016-03-17 11:28:10.004 EDT bob 56eacd05.cda postgres: >STATEMENT: ALTER ROLE joe; 

If audit logs are not generated when unsuccessful attempts to delete privileges/permissions occur, this is a finding.