Web Vulnerabilities Methodology

In every Web Pentest, there are several hidden and obvious places that might be vulnerable. This post is meant to be a checklist to confirm that you have searched for vulnerabilities in all the possible places.

Nowadays web applications usually uses some kind of intermediary proxies, those may be (ab)used to exploit vulnerabilities. These vulnerabilities need a vulnerable proxy to be in place, but they usually also need some extra vulnerability in the backend.

Most of the web applications will allow users to input some data that will be processed later. Depending on the structure of the data the server is expecting some vulnerabilities may or may not apply.

If the introduced data may somehow be reflected in the response, the page might be vulnerable to several issues.

Some of the mentioned vulnerabilities require special conditions, others just require the content to be reflected. You can find some interesting polygloths to test quickly the vulnerabilities in:

If the functionality may be used to search some kind of data inside the backend, maybe you can (ab)use it to search arbitrary data.

When a websocket posts a message or a form allowing users to perform actions vulnerabilities may arise.

Depending on the HTTP headers given by the web server some vulnerabilities might be present.

There are several specific functionalities where some workarounds might be useful to bypass them

Some functionalities will require the data to be structured in a very specific format (like a language serialized object or XML). Therefore, it's easier to identify if the application might be vulnerable as it needs to be processing that kind of data. Some specific functionalities may be also vulnerable if a specific format of the input is used (like Email Header Injections).

Functionalities that allow uploading files might be vulnerable to several issues. Functionalities that generate files including user input might execute unexpected code. Users that open files uploaded by users or automatically generated including user input might be compromised.