A bug dubbed Riddle vulnerability affecting MySQL 5.5 and 5.6 clients exposed user credentials to MiTM attacks. Update to version 5.7.
According to security researcher Pali Rohár, the Riddle vulnerability results for the failed attempt to patch the BACKRONYM vulnerability affecting the MySQL database. The Backronym vulnerability exposes passwords to attackers who are in a position to run a man-in-the-middle attack, even if the traffic is encrypted.
“Security update for the stable MySQL 5.5.49 and 5.6.30 versions consisted of adding a verification of security parameters after the authentication process was finished.” “Since it is done after the authentication, riddle in the middle attack together with SSL-downgrade attack can be used by the attacker to steal login data for immediate authentication and log into the MySQL server,” wrote Rohár.
“Ridiculous part is that MySQL client doesn’t report any SSL-related error when MySQL server declines to authenticate a user and instead reports unencrypted error message send by the server. Furthermore, the error message is controlled by the attacker, when the riddle in the middle attack is active.”
The expert suggests updating the client software to MySQL 5.7 or MariaDB, because the security updates for these applications correctly work.
The Riddle vulnerability was discovered in February, but today the bug still affect the Oracle MySql software.