Source summary
The Code Snippets WordPress plugin before 3.10.0 does not sanitise and escape a user-supplied parameter before using it in a SQL query in some of its snippet-migration import endpoints, which are accessible to any user holding site-administration capabilities; on a WordPress Multisite network those belong to subsite Administrators, allowing a subsite Administrator who is not a network Super Admin to perform UNION-based SQL injection against shared network tables and disclose network-wide data such as other users' password hashes.