Improper Handling of Undefined Values

Demonstrations

The following examples help to illustrate the nature of this weakness and describe methods or techniques which can be used to mitigate the risk.

Note that the examples here are by no means exhaustive and any given weakness may have many subtle varieties, each of which may require different detection methods or runtime controls.

Example One

In this example, an address parameter is read and trimmed of whitespace.

String address = request.getParameter("address");
address = address.trim();
String updateString = "UPDATE shippingInfo SET address='?' WHERE email='cwe@example.com'";
emailAddress = con.prepareStatement(updateString);
emailAddress.setString(1, address);

If the value of the address parameter is null (undefined), the servlet will throw a NullPointerException when the trim() is attempted.

See Also