All language subtitles for 001 An introduction to Same Origin Policy.en

Welcome back to another video.

In this video, we're going to talk about same origin policy.

Browsers are often used as claims to access applications, but in reality, a browser is one of the

most complicated software programs in your straight SIM origin policies, one of the features that many

browsers support to protect users from a variety of attacks.

Before we discuss about SIM origin policy, it is important to understand what origin is.

When content is loaded from different sources on the Web, browsers should be able to differentiate

between the content from different sources.

This is where origin comes into picture.

Origin is used to define different parties and draw boundaries between them more precisely, and this

origin is represented as steam host.

Portable scheme refers to the protocol used, for example, its GDP or hatred heterogeneous that we

almost always see.

And the host refers to the domain name and port refers to the port no configured on the web.

So if you see the example that is shown on the screen here, there are two domains here which are considered

to be from different origins.

The reason is in the first domain, the scheme is Hedgepeth, and in the second domain, the scheme

is heterodoxy.

That's one differentiator if the scheme is different.

These two domains are from two different origins.

Similarly, we can check the host.

The host in the first domain is legit dot com.

In case of the second domain it is evil.

Dot com, little dot com and even dot com are two different domains.

And there's these two domains are from different origins.

Similarly, the port in the first case is ForFour three by default because we are using IDP's and in

the second domain case the port is eight zero eight zero.

Once again, these ports can be used to determine if these two domains are from the same origin or not.

Remember, it is enough for one of these three to be different in these two domains.

For instance, Heggarty be able dot com eight zero eight zero is one domain and Heggarty be evil.

Dot com eight zero eight nine is another domain.

Since the port number in these two domains is different, they are still considered to be from different

origins.

So that's how origin is defined.

Communications between these different origins are generally known as cross origin interactions.

Though crosseyed and interactions are beneficial, they are also the cause of several netbacks.

Some cross origin requests can be potentially dangerous and can cause a change in the state of remote

server crosseyed request.

Forgery, or CSIR is an example of such an attack.

Now that we understood what origin is, let's try to understand the same origin policy, same origin

policy or S.O.P is a browser level security control which dictates how a document or script served by

one origin can interact with a resource from some other origin.

This ensures that scripts running under one origin cannot read data from another origin.

So by same origin policy, typically cross origin rights are allowed, but cross origin rights are typically

not allowed.

Even when it comes to cross origin rights.

There are some restrictions in certain cases where additional requests will be sent by the browser to

perform things like pre-flight checks, which is typically the case in XML HDB requests.

But typically HTML form submissions are allowed by same origin policy.

Now, keeping these concepts in mind, let's try to understand how some of the commonly seen vulnerability's

like crosseyed scripting and cost site request forgery are related to same audit in policy.

Let's first talk about cross site scripting.

As I mentioned earlier, cross origin groups are typically not allowed when you try to perform across

site scripting attack.

We typically try to execute JavaScript on the target domain and we try to read sensitive information

like cookies.

Now, this is typically not allowed by same origin policy, so you cannot set up an attacker's domain

and execute some JavaScript there in a way that it retrieves the cookies of the victims website.

And that's exactly the reason why you will have to find a way to execute JavaScript on the victims website.

That's Crosseyed scripting, so because of this same ideas in policy, Crossfade script cannot be performed

by executing JavaScript on an attacker controlled domain.

Now, when it comes to CSR of CSR, Rove is typically performed by submitting a form which can make

some state changes.

On the server side, you're not expecting to read any response from the server.

This means we are just required to make across our region.

Right, which is typically allowed by same Autogen policy.

So when you're conducting a quasi request forgery attack, you can host your payload on an attacker

controlled website.

So this is how Crosseyed scripting and CSR are related to seeing Autogen policy.

So same ideas in policy is a foundation to understand Crosseyed scripting and Crossfade request forgery

attacks.