Deep dive in CORS: History, how it works, and best practices

Re:Deep dive in CORS: History, how it works, and best practices by yashap on Wednesday April 14, 2021 @01:20AM (#26803215)

Though even still, the same-origin policy isn’t strict enough to prevent CSRF. For example, your browser will still send POSTs with Content Type application/x-www-form-urlencoded cross-origin, with cookies, even if it doesn’t let you read the response. That’s why we have to add complexity with anti-forgery tokens :/

It’ll be great when you can simply count on browsers having implemented strict SameSite cookies, because that’s such a simple, elegant solution. Anti-forgery tokens are a bit of a hack.

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Re:Deep dive in CORS: History, how it works, and best practices by danlugo92 on Wednesday April 14, 2021 @12:09PM (#26809068)

Isn't it easy to just block all `application/x-www-form-urlencoded` requests?

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Re:Deep dive in CORS: History, how it works, and best practices by yashap on Saturday April 17, 2021 @06:27PM (#26847991)

Most sites won’t want to do this, because HTML forms are useful! Also, that’s just one example, there are plenty of exemptions to the same origin policy: https://developer.mozilla.org/en-US/docs/Web/Security/Same-o...

In practice, for now you either use anti-forgery tokens, you don’t put your auth tokens in cookies, or you use strict SameSite auth cookies AND block all traffic from browsers that don’t support them (mostly legacy browsers).

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