Authentication Bypass
Authentication Bypass
Overview of the Vulnerability
Authentication bypass vulnerabilities allow an attacker to gain access to an account without having to go through the application's authentication procedure.
Authentication bypass often occurs through logic flaws and incomplete implementation of authentication mechanisms. Bypassing the authentication mechanisms of this application allows an attacker to view or edit data or other user's permissions, take over user accounts, access unauthorized endpoints, or expose critical data, depending on the authorization of the account they gain access to.
Business Impact
Authentication bypass can lead to data loss or theft through an attacker's access to data. The severity of which is dependent on the sensitivity of the data within the application. It can also result in reputational damage to the application or the company due to legitimate users not trusting the security of the application if the application's data becomes publicly available.
Steps to Reproduce
Navigate to: {{URL}} and login as a regular user
In the URL, change the
/userto/user/administratorObserve that the application now allows the user to view other user's profile details. These actions are usually restricted to an authenticated user
Proof of Concept (PoC)
The following image(s) show the full exploit:
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An attacker can bypass authentication or break session management to access the application's data.
Guidance
Provide a step-by-step walkthrough on how to access the vulnerable authentication mechanism and how to exploit the vulnerability to obtain access or perform a function that is intended to enforce authentication. Include instructions on how to access the vulnerable authentication mechanism and steps to bypass it in order to perform a function or access data not intended for that user. Provide screenshots to show the functionality accessed without valid authentication.
Explain why this bypass is a risk and how it can be used as an attack vector. If safe, perform a function that is shown to require authentication. If this is possible, provide a full Proof of Concept here.
Recommendation(s)
Authentication bypass can be remediated by implementing a handful of best practices relating to authentication and session management to ensure secure implementation. These include:
Keeping all systems, software and operating systems up-to-date with a repeatable patch management process
Validate all user input server-side
Ensure that the authentication mechanisms and logic are robust and that each request for a resource passes through an authorization process
The verification logic of the application, as well as all of the above, should be thoroughly tested during the development and QA phases of an application build.
For further information, refer to Open Web Application Security Project (OWASP):
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