An issue was discovered in phpMyAdmin. An unauthenticated user is able to execute a denial-of-service (DoS) attack by forcing persistent connections when phpMyAdmin is running with $cfg['AllowArbitraryServer']=true. All 4.6.x versions (prior to 4.6.4), 4.4.x versions (prior to 4.4.15.8), and 4.0.x versions (prior to 4.0.10.17) are affected.