Cross-site Scripting (XSS) is a client-side code injection attack where an attacker can execute malicious scripts into a website or web application. Stored Cross-Site Scripting affects the web applications that allows users to store data. This action can potentially expose the users to this type of attack. There are many web applications that are vulnerable to Stored Cross-site Scripting. These web applications fail to filter the stored inputs gathered from the users. As these stores that input in a data store for later use.
The Stored XSS attack can be successfully executed when a web application gathers malicious input from a user and then stores the input in a database for later use. The main reason for a successful stored XSS attack is the negligence by the developer. The developer had failed to filter the stored input properly. Due to this negligence, that malicious data will appear to be part of the web application and will run in the user’s browser using the web application’s privileges. As this vulnerability typically involves at least two requests to the application, it will also expose the user to second-order XSS.
The stored cross-site scripting vulnerability can be used to conduct a number of browser-based attacks including:-
A Stored XSS doesn’t require a malicious link to initiate. Successful exploitation can only be initiated when an end-user visits a page with a stored XSS vulnerability. The following are the phases that a typical site faces during a typical stored XSS attack scenario:-
Let us consider the following input field is vulnerable to a stored XSS attack.
The attacker will find ways to inject code into the vulnerable input box.
An attacker can perform attacks like:-
Beagle recommends the following fixes:-