I was asked how this code has a security risk.  Does anyone have any ideas what it is? I am new on the security topic and don't know what to look for.String DBdriver = com.ora.jdbc.Driver;String DataURL = jdbc:db://localhost:5112/users;String loginName = stackoverflow;String passwd = codeReview;Class.forName(DBdriver);Connection conn = DriverManager.getConnection(DataURL, loginName, passwd);String Username = request.getParameter(USER);String Password = request.getParameter(PASSWORD);int iUserID = -1;String loginUser = ;String sel = SELECT UserID, Username FROM USERS WHERE Username = '     +Username + ' AND Password = ' + Password + ';Statement selectStatement = conn.createStatement ();ResultSet result = selectStatement.executeQuery(sel);if (result.next()) {       iUserID = result.getInt(1);       loginUser = result.getString(2);}PrintWriter wr = response.getWriter ();if (iUserID >= 0) {       wr.println (you logged in:  + loginUser);} else {       wr.println (you cannot login in !Access Denied!)}
What is the security issue in this code?
java;security;interview questions