SQL injection vulnerability in admin/modules/user/users.php in MyBB (aka MyBulletinBoard) 1.6.6 allows remote attackers to execute arbitrary SQL commands via the conditions[usergroup][] parameter in a search action to admin/index.php.
Improper Neutralization of Special Elements used in an SQL Command 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.