Cross-site request forgery (csrf)

Definition

Cross-site request forgery (CSRF) is a type of attack where a malicious website tricks a user's browser into making an unwanted request to a different site where the user is authenticated. This exploit can lead to unauthorized actions being performed on behalf of the user, such as changing account settings or making purchases. CSRF takes advantage of the trust that a site has in a user's browser, making it a significant security concern in web applications.

5 Must Know Facts For Your Next Test

1. CSRF attacks often occur when users are logged into their accounts on vulnerable sites while unknowingly visiting a malicious site.
2. The attack can execute actions like changing passwords, transferring funds, or sending messages without the user's consent.
3. Preventive measures against CSRF include using anti-CSRF tokens, same-site cookies, and validating the referer header.
4. Unlike phishing, which involves tricking users into giving away their credentials, CSRF relies on exploiting authenticated sessions without needing user interaction.
5. Browsers do not distinguish between legitimate requests and those initiated by a CSRF attack, making awareness of this vulnerability crucial for developers.

Review Questions

• How does cross-site request forgery exploit the relationship between users and their authenticated sessions?
  • Cross-site request forgery exploits the trust that a website has in the user's browser by sending unauthorized requests on behalf of an authenticated user. When a user is logged into a site, their session cookies are automatically sent with any request from their browser. An attacker can craft a malicious request to trigger actions on that site while the user is unaware, leveraging the existing authentication without needing to hijack credentials directly.
• What are effective strategies to mitigate cross-site request forgery attacks in web applications?
  • To mitigate cross-site request forgery attacks, web applications can implement several strategies such as using anti-CSRF tokens that are unique for each session and verified with each state-changing request. Additionally, setting same-site cookie attributes restricts cookies to first-party contexts, reducing exposure to CSRF. Validating the referer header can also help ensure that requests originate from trusted sources. These practices collectively strengthen the defenses against potential CSRF vulnerabilities.
• Evaluate the impact of cross-site request forgery on web application security and its implications for user trust.
  • Cross-site request forgery significantly impacts web application security as it undermines user trust by enabling unauthorized actions without consent. If users experience or learn about CSRF attacks on trusted platforms, they may feel insecure about using these services, leading to reduced engagement or abandonment of those platforms. This erosion of trust not only affects individual applications but can also have broader implications for online security standards, prompting developers to prioritize robust anti-CSRF measures and reinforcing the necessity of educating users about web vulnerabilities.

Related terms

XSS (Cross-Site Scripting): A vulnerability that allows an attacker to inject malicious scripts into web pages viewed by users, potentially compromising their data.

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

CSRF Token: A unique, secret value generated by the server and included in forms and requests to verify that the request comes from the authenticated user, mitigating CSRF attacks.