4
votes
1answer
490 views

Does returning `Access-Control-Allow-Origin: *` weaken the security of JSON GET responses?

The W3C CORS recommendation states: Certain types of resources should not attempt to specify particular authorized origins, but instead either deny or allow all origins. ... 3. A GET ...
12
votes
2answers
19k views

Why is the Access-Control-Allow-Origin header necessary?

I understand the purpose of the Access-Control-Allow-Credentials header, but can't see what problem the Access-Control-Allow-Origin header solves. More precisely, it's easy to see how, if ...
1
vote
1answer
413 views

Why is Access-Control-Allow-Origin required for uncredentialed cross-domain requests?

I understand CSRF and why cross-domain AJAX requests with cookies or other credentials can't be permitted without an Access-Control-Allow-Credentials header explicitly permitting them - otherwise I'd ...
1
vote
3answers
317 views

Why can I read the response to this CSRF attack?

I have a website www.foo.com:8002 that I have resolve to 127.0.0.1:8002 in my hosts file. I have another (the main site) running at localhost:80 In www.foo.com:8002 the page looks like <form ...