Multiple SQL injection vulnerabilities in pie-register/pie-register.php in the Pie Register plugin before 2.0.19 for WordPress allow remote administrators to execute arbitrary SQL commands via the (1) select_invitaion_code_bulk_option or (2) invi_del_id parameter in the pie-invitation-codes page to wp-admin/admin.php.
The product constructs all or part of an SQL command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended SQL command when it is sent to a downstream component. Without sufficient removal or quoting of SQL syntax in user-controllable inputs, the generated SQL query can cause those inputs to be interpreted as SQL instead of ordinary user data.