Cross-Site Request Forgery

Definition

Cross-site request forgery (CSRF) is a type of attack that tricks a user into performing actions on a web application in which they are authenticated without their consent. This attack occurs when a malicious website sends unauthorized commands to a web application on behalf of the victim, taking advantage of the user's active session. CSRF exploits the trust that a site has in the user's browser and can lead to unauthorized transactions or data changes.

5 Must Know Facts For Your Next Test

1. CSRF attacks can be particularly damaging because they exploit the trust between the user and the application, making them hard to detect.
2. To mitigate CSRF attacks, many applications implement anti-CSRF tokens that must be included in requests to validate their legitimacy.
3. The attacker often sends a link via email or a malicious webpage, which triggers the unwanted action without the user's knowledge.
4. CSRF can affect any authenticated web application, especially those that allow state-changing actions like transferring money or changing passwords.
5. Preventive measures against CSRF should also include validating HTTP referer headers to ensure requests are coming from trusted sources.

Review Questions

• What are some common techniques used to mitigate cross-site request forgery attacks, and how do they function?
  • Common techniques to mitigate cross-site request forgery attacks include using CSRF tokens and implementing same-origin policies. CSRF tokens work by generating unique tokens for each user session that must be submitted with any state-changing requests. This way, if an attacker tries to forge a request, they won't have access to the correct token. Same-origin policies prevent unauthorized websites from interacting with the web application, thereby adding another layer of protection against CSRF.
• Analyze how the implementation of anti-CSRF tokens can enhance the security of web applications against CSRF attacks.
  • The implementation of anti-CSRF tokens significantly enhances web application security by ensuring that every form submission includes a unique token generated for each session. This token acts as a proof of authenticity, making it nearly impossible for an attacker to predict or forge a valid request. If a request is made without the correct token, the server can reject it, effectively preventing unauthorized actions even if an attacker manages to trick the user into initiating a request.
• Evaluate the implications of cross-site request forgery on user trust and data integrity in online transactions.
  • Cross-site request forgery has serious implications for user trust and data integrity in online transactions. If users become victims of CSRF attacks, they may unknowingly authorize significant actions such as fund transfers or changes to personal information, leading to financial losses and compromised accounts. Such incidents can erode trust in the affected web applications and service providers. Therefore, addressing CSRF vulnerabilities is crucial not only for protecting user data but also for maintaining confidence in online services.

Related terms

CSRF Token: A unique, secret value generated by the server and included in forms submitted by users, ensuring that requests come from authorized sources.

Same-Origin Policy: A security measure that restricts how documents or scripts loaded from one origin can interact with resources from another origin, helping to prevent attacks like CSRF.

Session Fixation: An attack that exploits the web application's session management system by forcing a user to use a specific session ID that an attacker controls.