How to analyze and simply protect XSS from the point of view of code

This article will explain in detail how to analyze and simply protect XSS from the code point of view. The content of the article is of high quality. Therefore, Xiaobian shares it with you as a reference. I hope that after reading this article, you will have a certain understanding of relevant knowledge.

Xss in the usual test, or more important, if there is a storage type xss, you can do a lot of things, hit cookies, add administrators and many other operations.

All the following code is written by myself, there may be unsightly, code errors and so on, I hope you can correct me.

Bug explanation

This is an input box.

Write classic pop-up code inside

Click Submit and go to index.php

A pop-up code appears.

Here, add the code used earlier

The reason is that the input is not filtered and stored directly in the database

Simple repair

You just need to filter the content as it comes in.

Here we mainly use the htmlspecialchars() function, this function can convert its content into HTML entities, it is perfect to prevent xss vulnerabilities

We just need to process it when we insert it into the database

At this point, look at the effect

At this point, the window is no longer pop-up

At this point the tag has been escaped as an HTML entity

expand

In fact, the role of xss is still very large, definitely not limited to cookies, etc., before seeing a more interesting article, said that the pose is a mess in the background, the essence is to use xss and then combine some other things to achieve, so that the idea must be open, not limited to a vulnerability itself that a few use points.

About how to analyze and simply protect XSS from the code point of view to share here, I hope the above content can be of some help to everyone, you can learn more knowledge. If you think the article is good, you can share it so that more people can see it.