This category includes weaknesses that occur when an application does not properly handle errors that occur during processing.
Extended Description
An attacker may discover this type of error, as forcing these errors can occur with a variety of corrupt input.
Common Consequences
Scope
Effect
Integrity
Confidentiality
Technical Impact: Read application
data; Modify files or
directories
Generally, the consequences of improper error handling are the
disclosure of the internal workings of the application to the attacker,
providing details to use in further attacks. Web applications that do
not properly handle error conditions frequently generate error messages
such as stack traces, detailed diagnostics, and other inner details of
the application.
Demonstrative Examples
Example 1
In the snippet below, an unchecked runtime exception thrown from
within the try block may cause the container to display its default error
page (which may contain a full stack trace, among other
things).
(Bad Code)
Example
Language: Java
Public void doPost(HttpServletRequest request, HttpServletResponse
response) throws ServletException, IOException {
try {
...
}
catch (ApplicationSpecificException ase) {
logger.error("Caught: " + ase.toString());
}
}
Potential Mitigations
Use a standard exception handling mechanism to be sure that your
application properly handles all types of processing errors. All error
messages sent to the user should contain as little detail as necessary
to explain what happened.
If the error was caused by unexpected and likely malicious input, it
may be appropriate to send the user no error message other than a simple
"could not process the request" response.
The details of the error and its cause should be recorded in a
detailed diagnostic log for later analysis. Do not allow the application
to throw errors up to the application container, generally the web
application server.
Be sure that the container is properly configured to handle errors if
you choose to let any errors propagate up to it.
Description
