An issue was discovered in phpMyAdmin. An unauthenticated user can execute a denial of service attack when phpMyAdmin is running with $cfg['AllowArbitraryServer']=true. All 4.6.x versions (prior to 4.6.5), 4.4.x versions (prior to 4.4.15.9), and 4.0.x versions (prior to 4.0.10.18) are affected.
https://www.phpmyadmin.net/security/PMASA-2016-65