MySQL Bugs: #74486: Dangerous grant in rewrite plugin install script

Bug #74486	Dangerous grant in rewrite plugin install script
Submitted:	21 Oct 2014 18:55	Modified:	16 Feb 2015 20:37
Reporter:	Daniël van Eeden (OCA)	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Server: Installing	Severity:	S3 (Non-critical)
Version:	5.7.5-labs-preview	OS:	Any
Assigned to:		CPU Architecture:	Any
Tags:	grants, rewriter plugin

Description:
File: lib/plugin/install_rewriter_plugin.sql

One piece of the script:
GRANT SELECT ON query_rewrite.rewrite_rules TO root@localhost;
GRANT INSERT ON query_rewrite.rewrite_rules TO root@localhost;
GRANT UPDATE ON query_rewrite.rewrite_rules TO root@localhost;

In MySQL Enterprise Monitor there is an advisor rule which advises you to rename the root account. There are also some security benchmarks which recommend this. I don't think this should be done, but some people might have done this.

If the script is executed with a renamed root account then the root account will be created without password.

How to repeat:
Rename root@localhost as advised by MEM.
Run the install script for the rewriter plugin.
Run 'SHOW GRANTS FOR root@localhost'.

Suggested fix:
Add "SET SESSION sql_mode='NO_AUTO_CREATE_USER'" to make sure it won't create an account by accident.

Check if "SELECT COUNT(*) FROM mysql.user WHERE User='root' AND Host='localhost'" returns more than 0 rows.

Implement RFE Bug #73802

If root@localhost is used this should also be used as definer for the query_rewrite.flush_rewrite_rules procedure (also created with the install script).

Also the hardcoded ".so" should be made dynamic as ".dll" will be used on Microsoft Windows.

Hello Daniël,

Thank you for the bug report.

Thanks,
Umesh

This has been fixed on the feature tree.