What is the SameSite attribute in CSRF protection?
SameSite is a cookie attribute (similar to HTTPOnly, Secure etc.) which aims to mitigate CSRF attacks. It is defined in RFC6265bis. This attribute helps the browser decide whether to send cookies along with cross-site requests.
Why are CSRF attacks possible against web apps?
CSRF attacks are possible against web apps that use cookies for authentication because: Browsers store cookies issued by a web app. Stored cookies include session cookies for authenticated users.
How does cross-site request forgery ( CSRF ) attack work?
Cross-Site Request Forgery (CSRF) is a type of attack that occurs when a malicious web site, email, blog, instant message, or program causes a user’s web browser to perform an unwanted action on a trusted site when the user is authenticated. A CSRF attack works because browser requests automatically include all cookies including session cookies.
Can a CSRF token be transmitted using cookies?
CSRF tokens should not be transmitted using cookies. The CSRF token can be added through hidden fields, headers, and can be used with forms, and AJAX calls. Make sure that the token is not leaked in the server logs, or in the URL.
Why are GET requests not used in CSRF?
Another reason for not using GET requests is that cookies set to Lax are still sent along with GET requests, giving attackers another opportunity to exploit users. Lastly, exploiting a CSRF vulnerability by using GET is much easier. To exploit a CSRF vulnerability in a form using GET, an attacker does not have to own a site.
Which is the best framework for CSRF protection?
It is strongly recommended to research if the framework you are using has an option to achieve CSRF protection by default before trying to build your custom token generating system. For example, .NET has built-in protection that adds a token to CSRF vulnerable resources.
Can a CSRF attack distinguish between legitimate and forged requests?
Therefore, if the user is authenticated to the site, the site cannot distinguish between legitimate requests and forged requests. The impact of a successful CSRF attack is limited to the capabilities exposed by the vulnerable application and privileges of the user.
What do you look to exploit with CSRF?
“Double Submit” CSRF Token method. What areas in a webapp do you look to exploit with CSRF? Anywhere there might be a PUT request on the back-end. You are able to exploit this with a GET request as well, but the odds of finding this in the wild are very small as most devs know better by now.
What is the double submit defense against CSRF?
This is sometimes called the “double submit” defense against CSRF, and is advocated because it is simple to implement and avoids the need for any server-side state. In the above request, it’s important to notice how the csrf session token matches the csrf parameter.