The Web Application Hacker’s Handbook Discovering and Exploiting Security Flaws

Think imaginatively about any other possible means by which data you

control may be stored by the application and displayed to other users.

For example, if the application search function shows a list of popular

search items, you may be able to introduce a stored XSS payload by

searching for it numerous times, even though the primary search func-

tionality itself handles your input safely.

When you have identified every instance in which user-controllable data is

stored by the application and later displayed back to the browser, you should fol-

low the same process described previously for investigating potential reflected

XSS vulnerabilities — that is, determine what input needs to be submitted to

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embed valid JavaScript within the surrounding HTML and then attempt to cir-

cumvent any filters which interfere with the processing of your attack 

payload.

T I P