CWE-537: Java Runtime Error Message Containing Sensitive Information

In many cases, an attacker can leverage the conditions that cause unhandled exception errors in order to gain unauthorized access to the system.

Recorded CVEs

With this primary weakness

KEVs

In the CISA KEV catalog

Not rated

Likelihood of exploit

Per MITRE

Variant

Abstraction

MITRE classification

Overview

CWE-537 (Java Runtime Error Message Containing Sensitive Information) is a variant-level software weakness catalogued by MITRE in the Common Weakness Enumeration (CWE). It describes a recurring type of mistake that can lead to exploitable security vulnerabilities.

Code examples

Illustrative examples from MITRE showing how the weakness appears in code.

In the following Java example the class InputFileRead enables an input file to be read using a FileReader object. In the constructor of this class a default input file path is set to some directory on the local file system and the method setInputFile must be called to set the name of the input file to be read in the default directory. The method readInputFile will create the FileReader object and will read the contents of the file. If the method setInputFile is not called prior to calling the method readInputFile then the File object will remain null when initializing the FileReader object. A Java RuntimeException will be raised, and an error message will be output to the user.

Vulnerable example

java

public class InputFileRead {

However, the error message output to the user contains information regarding the default directory on the local file system. This information can be exploited and may lead to unauthorized access or use of the system. Any Java RuntimeExceptions that are handled should not expose sensitive information to the user.

In the example below, the BankManagerLoginServlet servlet class will process a login request to determine if a user is authorized to use the BankManager Web service. The doPost method will retrieve the username and password from the servlet request and will determine if the user is authorized. If the user is authorized the servlet will go to the successful login page. Otherwise, the servlet will raise a FailedLoginException and output the failed login message to the error page of the service.

Vulnerable example

java

public class BankManagerLoginServlet extends HttpServlet {

However, the output message generated by the FailedLoginException includes the user-supplied password. Even if the password is erroneous, it is probably close to the correct password. Since it is printed to the user's page, anybody who can see the screen display will be able to see the password. Also, if the page is cached, the password might be written to disk.

CWE-537: Java Runtime Error Message Containing Sensitive Information

Overview

Common consequences

How it happens

When it is introduced

Applies to

How to prevent it

Code examples

Frequently asked questions

What is CWE-537?

How do you prevent CWE-537?

What are the consequences of CWE-537?

References

Stay ahead of CWE-537

Overview

Common consequences

How it happens

When it is introduced

Applies to

How to prevent it

Code examples

Related weaknesses

Parent

Frequently asked questions

What is CWE-537?

How do you prevent CWE-537?

What are the consequences of CWE-537?

References

Stay ahead of CWE-537