Recently, while doing a test process to examine resource usage and the time required to alter the table using pt-osc, it leads to a loss of triggers even though the –preserve-triggers option is specified. I made the decision to recreate the identical circumstance so that everyone could see it.

Test environment : 

OS: Amazon Linux 2

MySQL version: 5.7.40

pt-online-schema-change version: 3.1.0

Before digging deeper, we must first obtain the whole picture. Here is an illustration of the table’s structure.

Table structure:

This is an update for MySQL 8 Stored PSM to add the ONLY_FULL_GROUP_BY mode to the global SQL_MODE variable when it’s not set during a session. Here’s the code:

/* Drop procedure conditionally on whether it exists already. */
DROP PROCEDURE IF EXISTS set_full_group_by;

/* Reset delimter to allow semicolons to terminate statements. */
DELIMITER $$

/* Create a procedure to verify and set connection parameter. */
CREATE PROCEDURE set_full_group_by()
  LANGUAGE SQL
  NOT DETERMINISTIC
  SQL SECURITY DEFINER
  COMMENT 'Set connection parameter when not set.'
BEGIN

  /* Check whether full group by is set in the connection and
     if unset, set it in the scope of the connection. */
  IF EXISTS
    (SELECT TRUE
     WHERE NOT REGEXP_LIKE(@@SESSION.SQL_MODE,'ONLY_FULL_GROUP_BY'))
  THEN
    SET @@GLOBAL.SQL_MODE := CONCAT(@@SESSION.sql_mode,',ONLY_FULL_GROUP_BY');
  END IF;
END;
$$

/* Reset the default delimiter. */
DELIMITER ;

You can call the …

Knex recently released a new version this week (2.4.0). Before this version, Knex had a pretty scary SQL injection. Knex currently has 1.3 million weekly downloads and is quite popular.

The security bug is probably one of the worst SQL injections I’ve seen in recent memory, especially considering the scope and popularity.

If you want to get straight to the details:

• Check out the Github issue, which was opened 7 years ago(!)
• An article from Ghostccamm explaining the vulnerability.
• CVE-2016-20018.

My understanding of this bug

If I understand the vulnerability correctly, I …

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