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And this lecture and the next few lectures we're going to talk about a vulnerability called Access has

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access is short for a cross-site scripting this type of vulnerability allows an attacker to inject javascript

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into a page so Javascript is a programming language and using this vulnerability an attacker would be

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able to execute code written in javascript into a certain page into a website Javascript is a client

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site language.

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So when the code is executed it will be executed on the client on the user on the person who is browsing

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the web page.

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Its not going to be executed on the server.

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So even if your code results into giving you a reverse shell the shell will be coming from the user

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who is browsing the page and its not going to be coming from the Web site.

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So any code you write in javascript will be exploited or will run on the target user on the people who

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see the pages and its not on the web server so the web server is only going to be used as means of executing

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the code or delivering the code.

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There three main types of access as vulnerabilities is persistent or stored reflected and Home-Based

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the stored access gets stored into the database.

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So the code that you inject will be stored into the database or into the page so that every time any

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person views that page your code will be executed.

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And reflected one the code will only be executed when the target user runs a specific cure all crafted

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or written by you.

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So you'll be manipulating some sort of your L and send it to a target and when they run that target

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when they run that.

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The code will be executed

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don't based results from javascript code written on the client.

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So the code will actually be interpreted and run on the client side without having any communication

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with the web server.

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This could be very dangerous because sometimes web servers apply some sort of security infiltration

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to check for access.

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But with Home-Based the code never gets sent to the web server.

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So the call will be interpreted and run on the web browser without even interacting with the web server

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and these will be present into websites that update their content.

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With that refresh so we've all used Web sites where you put your username for example and it loads in

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straight away without having to check with the web server.

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Or do you put some sort of a string and it doesn't search without communicating with the web server

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or does something with communicating with a web server.

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So if you're able to inject into that then this injection will not be validated.

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So it will be executed straightaway and bypass all validations.