The MySQL Database Server 8.0 must generate audit records when unsuccessful attempts to modify categories of information (e.g., classification levels/security levels) occur.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-235118	MYS8-00-003100	SV-235118r638812_rule		Medium

Description
Changes in categories of information must be tracked. Without an audit trail, unauthorized access to protected data could go undetected. To aid in diagnosis, it is necessary to keep track of failed attempts in addition to the successful ones. For detailed information on categorizing information, refer to FIPS Publication 199, Standards for Security Categorization of Federal Information and Information Systems, and FIPS Publication 200, Minimum Security Requirements for Federal Information and Information Systems.

Description

Changes in categories of information must be tracked. Without an audit trail, unauthorized access to protected data could go undetected. To aid in diagnosis, it is necessary to keep track of failed attempts in addition to the successful ones. For detailed information on categorizing information, refer to FIPS Publication 199, Standards for Security Categorization of Federal Information and Information Systems, and FIPS Publication 200, Minimum Security Requirements for Federal Information and Information Systems.

STIG	Date
Oracle MySQL 8.0 Security Technical Implementation Guide	2021-02-08

Details

Check Text ( C-38337r623474_chk )
If classification levels/security levels labeling is not required, this is not a finding. Review the system documentation to determine if MySQL Server is required to audit records when unsuccessful attempts to modify categories of information (e.g., classification levels/security levels) occur. Check if MySQL audit is configured and enabled. The my.cnf file will set the variable audit_file. To further check, execute the following query: SELECT PLUGIN_NAME, PLUGIN_STATUS FROM INFORMATION_SCHEMA.PLUGINS WHERE PLUGIN_NAME LIKE 'audit%'; The status of the audit_log plugin should be "active". If it is not "active", this is a finding. Review audit filters and associated users by running the following queries: SELECT `audit_log_filter`.`NAME`, `audit_log_filter`.`FILTER` FROM `mysql`.`audit_log_filter`; SELECT `audit_log_user`.`USER`, `audit_log_user`.`HOST`, `audit_log_user`.`FILTERNAME` FROM `mysql`.`audit_log_user`; All currently defined audits for the MySQL server instance will be listed. If no audits are returned, this is a finding. Create MySQL insert, update, and delete triggers that check for changes to categories of information. If the trigger before data indicates an attempt to delete such information, the trigger should be written to prevent the delete as well as optionally write to the MySQL Audit by calling the audit_api_message_emit_udf() function and including the details related to the attempt. Note: To call from a trigger requires a minimal stored procedure as well. Once the trigger has been created, check if the audit filters that are in place are generating records when categories of information are deleted. - An Example test - CREATE TABLE `test_trigger`.`info_cat_test` ( `id` INT NOT NULL, `name` VARCHAR(20) NULL, `desc` VARCHAR(20) NULL, `sec_level` CHAR(1) NULL, PRIMARY KEY (`id`)); use test_trigger; DELIMITER $$ CREATE TRIGGER audit_delete BEFORE DELETE ON `test_trigger`.`info_cat_test` FOR EACH ROW BEGIN IF OLD.sec_level = 'H' THEN CALL audit_api_message_emit_sp(OLD.name); SIGNAL SQLSTATE '45000' SET MESSAGE_TEXT = 'ERROR - THIS DATA IS LEVEL H can not delete’; END IF; END$$ DELIMITER ; DELIMITER $$ CREATE TRIGGER audit_insert BEFORE INSERT ON `test_trigger`.`info_cat_test` FOR EACH ROW BEGIN IF NEW.sec_level = 'H' THEN CALL audit_api_message_emit_sp(NEW.name); SIGNAL SQLSTATE '45000' SET MESSAGE_TEXT = 'ERROR - THIS DATA IS LEVEL H can not insert’; END IF; END$$ DELIMITER ; DELIMITER $$ CREATE TRIGGER audit_update BEFORE UPDATE ON `test_trigger`.`info_cat_test` FOR EACH ROW BEGIN IF OLD.sec_level = 'H' THEN CALL audit_api_message_emit_sp(OLD.name); END IF; IF NEW.sec_level = 'H' THEN CALL audit_api_message_emit_sp(NEW.name); END IF; SIGNAL SQLSTATE '45000' SET MESSAGE_TEXT = 'ERROR - THIS DATA IS LEVEL H can not update'; END$$ DELIMITER ; INSERT INTO `test_trigger`.`info_cat_test` (`id`, `name`, `desc`, `sec_level`) VALUES ('1', 'fred', 'engineer', 'H'); INSERT INTO `test_trigger`.`info_cat_test` (`id`, `name`, `desc`, `sec_level`) VALUES ('2', 'jill', 'program manager', 'M'); INSERT INTO `test_trigger`.`info_cat_test` (`id`, `name`, `desc`, `sec_level`) VALUES ('3', 'joe', 'maintenance', 'L'); delete from `test_trigger`.`info_cat_test` where id=1; // this fails as the trigger defines that sec_level of H can not be deleted. update`test_trigger`.`info_cat_test` set sec_level=‘H’ where id=2; delete from `test_trigger`.`info_cat_test` where id=3; Review the audit log by running the Linux command: sudo cat /audit.log \| egrep audit_change_attempt For example if the values returned by - "select @@datadir, @@audit_log_file; " are /usr/local/mysql/data/, audit.log sudo cat /usr/local/mysql/data/audit.log \|egrep audit_change_attempt If the audit event is not present, this is a finding.

Check Text ( C-38337r623474_chk )

If classification levels/security levels labeling is not required, this is not a finding.

Review the system documentation to determine if MySQL Server is required to audit records when unsuccessful attempts to modify categories of information (e.g., classification levels/security levels) occur.

Check if MySQL audit is configured and enabled. The my.cnf file will set the variable audit_file.

To further check, execute the following query:
SELECT PLUGIN_NAME, PLUGIN_STATUS
FROM INFORMATION_SCHEMA.PLUGINS
WHERE PLUGIN_NAME LIKE 'audit%';

The status of the audit_log plugin should be "active". If it is not "active", this is a finding.

Review audit filters and associated users by running the following queries:
SELECT `audit_log_filter`.`NAME`,
`audit_log_filter`.`FILTER`
FROM `mysql`.`audit_log_filter`;

SELECT `audit_log_user`.`USER`,
`audit_log_user`.`HOST`,
`audit_log_user`.`FILTERNAME`
FROM `mysql`.`audit_log_user`;

All currently defined audits for the MySQL server instance will be listed. If no audits are returned, this is a finding.

Create MySQL insert, update, and delete triggers that check for changes to categories of information. If the trigger before data indicates an attempt to delete such information, the trigger should be written to prevent the delete as well as optionally write to the MySQL Audit by calling the audit_api_message_emit_udf() function and including the details related to the attempt. Note: To call from a trigger requires a minimal stored procedure as well.

Once the trigger has been created, check if the audit filters that are in place are generating records when categories of information are deleted.

- An Example test -

CREATE TABLE `test_trigger`.`info_cat_test` (
`id` INT NOT NULL,
`name` VARCHAR(20) NULL,
`desc` VARCHAR(20) NULL,
`sec_level` CHAR(1) NULL,
PRIMARY KEY (`id`));

use test_trigger;

DELIMITER $$

CREATE TRIGGER audit_delete
BEFORE DELETE ON `test_trigger`.`info_cat_test`
FOR EACH ROW
BEGIN
IF OLD.sec_level = 'H' THEN
CALL audit_api_message_emit_sp(OLD.name);
SIGNAL SQLSTATE '45000'
SET MESSAGE_TEXT = 'ERROR - THIS DATA IS LEVEL H can not delete’;
END IF;
END$$
DELIMITER ;

DELIMITER $$

CREATE TRIGGER audit_insert
BEFORE INSERT ON `test_trigger`.`info_cat_test`
FOR EACH ROW
BEGIN
IF NEW.sec_level = 'H' THEN
CALL audit_api_message_emit_sp(NEW.name);
SIGNAL SQLSTATE '45000'
SET MESSAGE_TEXT = 'ERROR - THIS DATA IS LEVEL H can not insert’;
END IF;
END$$
DELIMITER ;

DELIMITER $$

CREATE TRIGGER audit_update
BEFORE UPDATE ON `test_trigger`.`info_cat_test`
FOR EACH ROW
BEGIN
IF OLD.sec_level = 'H' THEN
CALL audit_api_message_emit_sp(OLD.name);
END IF;
IF NEW.sec_level = 'H' THEN
CALL audit_api_message_emit_sp(NEW.name);
END IF;
SIGNAL SQLSTATE '45000'
SET MESSAGE_TEXT = 'ERROR - THIS DATA IS LEVEL H can not update';
END$$
DELIMITER ;

INSERT INTO `test_trigger`.`info_cat_test` (`id`, `name`, `desc`, `sec_level`) VALUES ('1', 'fred', 'engineer', 'H');
INSERT INTO `test_trigger`.`info_cat_test` (`id`, `name`, `desc`, `sec_level`) VALUES ('2', 'jill', 'program manager', 'M');
INSERT INTO `test_trigger`.`info_cat_test` (`id`, `name`, `desc`, `sec_level`) VALUES ('3', 'joe', 'maintenance', 'L');

delete from `test_trigger`.`info_cat_test` where id=1;
// this fails as the trigger defines that sec_level of H can not be deleted.

update`test_trigger`.`info_cat_test` set sec_level=‘H’ where id=2;
delete from `test_trigger`.`info_cat_test` where id=3;

Review the audit log by running the Linux command:
sudo cat /audit.log | egrep audit_change_attempt
For example if the values returned by - "select @@datadir, @@audit_log_file; " are /usr/local/mysql/data/, audit.log
sudo cat /usr/local/mysql/data/audit.log |egrep audit_change_attempt

If the audit event is not present, this is a finding.

Fix Text (F-38300r623475_fix)
If currently required, configure the MySQL Database Server with update, insert, and delete triggers that call audit_api_message_emit_udf() function to produce audit records when unsuccessful attempts to modify categories of information occur. Add security level details in an additional column. Add the component for adding information to the audit log. INSTALL COMPONENT "file://component_audit_api_message_emit”; create schema test_trigger; Create a stored procedure to allow the audit_api_message_emit_udf to be called as well as providing the details for the audit event. DELIMITER $$ CREATE PROCEDURE audit_api_message_emit_delete_sp(name CHAR(20)) BEGIN DECLARE aud_msg VARCHAR(255); select audit_api_message_emit_udf('sec_level_trigger', 'TRIGGER audit_change_attempt', 'Attempt was made to change H level sec data', 'FOR ', name ) into aud_msg; END$$ DELIMITER ; See the supplemental file "MySQL80Audit.sql".

Fix Text (F-38300r623475_fix)

If currently required, configure the MySQL Database Server with update, insert, and delete triggers that call audit_api_message_emit_udf() function to produce audit records when unsuccessful attempts to modify categories of information occur.

Add security level details in an additional column.

Add the component for adding information to the audit log.

INSTALL COMPONENT "file://component_audit_api_message_emit”;
create schema test_trigger;

Create a stored procedure to allow the audit_api_message_emit_udf to be called as well as providing the details for the audit event.

DELIMITER $$

CREATE PROCEDURE audit_api_message_emit_delete_sp(name CHAR(20))
BEGIN
DECLARE aud_msg VARCHAR(255);
select audit_api_message_emit_udf('sec_level_trigger',
'TRIGGER audit_change_attempt',
'Attempt was made to change H level sec data',
'FOR ', name
) into aud_msg;
END$$
DELIMITER ;

See the supplemental file "MySQL80Audit.sql".