Oracle MySQL before 5.7.3, Oracle MySQL Connector/C (aka libmysqlclient) before...

Vulnerability Description

Oracle MySQL before 5.7.3, Oracle MySQL Connector/C (aka libmysqlclient) before 6.1.3, and MariaDB before 5.5.44 use the --ssl option to mean that SSL is optional, which allows man-in-the-middle attackers to spoof servers via a cleartext-downgrade attack, aka a "BACKRONYM" attack.

References

• http://packetstormsecurity.com/files/131688/MySQL-SSL-TLS-Downgrade.html
• http://mysqlblog.fivefarmers.com/2015/04/29/ssltls-in-5-6-and-5-5-ocert-advisory/
• http://www.securityfocus.com/bid/74398
• https://github.com/mysql/mysql-server/commit/3bd5589e1a5a93f9c224badf983cd65c45215390
• https://access.redhat.com/security/cve/cve-2015-3152
• http://rhn.redhat.com/errata/RHSA-2015-1646.html
• http://www.debian.org/security/2015/dsa-3311
• http://mysqlblog.fivefarmers.com/2014/04/02/redefining-ssl-option/
• http://rhn.redhat.com/errata/RHSA-2015-1647.html
• http://www.securitytracker.com/id/1032216
• https://www.duosecurity.com/blog/backronym-mysql-vulnerability
• https://jira.mariadb.org/browse/MDEV-7937
• http://www.ocert.org/advisories/ocert-2015-003.html
• http://lists.fedoraproject.org/pipermail/package-announce/2015-July/161625.html
• http://www.securityfocus.com/archive/1/535397/100/1100/threaded
• http://lists.fedoraproject.org/pipermail/package-announce/2015-July/161436.html
• http://rhn.redhat.com/errata/RHSA-2015-1665.html