The ssl_verify_server_cert function in sql-common/client.c in MariaDB before 5.5.47, 10.0.x before 10.0.23, and 10.1.x before 10.1.10, Oracle MySQL, and Percona Server do not properly verify that the server hostname matches a domain name in the subject's Common Name (CN) or subjectAltName field of the X.509 certificate, which allows man-in-the-middle attackers to spoof SSL servers via a /CN= string in a field in a certificate, as demonstrated by /OU=/CN=bar.com/CN=foo.com. http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-2047
