Testing for Bypassing Authorization Schema (OTG-AUTHZ-002)
This article is part of the OWASP Testing Guide v3. The entire OWASP Testing Guide v3 can be downloaded here.
OWASP at the moment is working at the OWASP Testing Guide v4: you can browse the Guide here
This kind of test focuses on verifying how the authorization schema has been implemented for each role/privilege to get access to reserved functions/resources.
Description of the Issue
For every specific role the tester holds during the assessment, for every function and request that the application executes during the post-authentication phase, it is necessary to verify:
- Is it possible to access that resource even if the user is not authenticated?
- Is it possible to access that resource after the log-out?
- Is it possible to access functions and resources that should be accessible to a user that holds a different role/privilege?
- Try to access the application as an administrative user and track all the administrative functions. Is it possible to access administrative functions also if the tester is logged as a user with standard privileges?
- Is it possible to use these functionalities for a user with a different role and for whom that action should be denied?
Black Box testing and example
Testing for Admind functionalities
For example if the application 'AddUser.jsp' is a part of the administrative menu of the application, and it is possible to access request the following URL:
The following HTTP request is generated calling the AddUser function:
POST /admin/addUser.jsp HTTP/1.1 Host: www.example.com [others HTTP headers]
What if a not adimistrative user try to execute that request? The user will be created? He can use his privileges?
Testing for access to resources assigned to a different role
Analyze for example an applicaton that uses a shared directory to store temporary pdf file to gives to the user. documentABC.pdf should be accessible only by the user test1 with roleA. Verify is user test2 wiht roleB can access to that resource.
Execute administrative functions or access to administrative resources as a standard user.
Gray Box testing and example
Testing for Topic X vulnerabilities: