CSRF Attacks

A Cross-Site Request Forgery (CSRF) attack tricks a user into making unauthorized changes to an app by executing malicious requests from a website they trust. It exploits the trust a user has in a website to manipulate them into performing unwanted actions on a third-party app.

Also Known As One-click Attack, Session Riding, XSRF (Cross-Site Request Forgery), Sea Surf, Session Riding,  Cross-Site Reference Forgery, and Hostile Linking

These sinister exploit targets vulnerabilities in web applications to carry out unwanted actions on behalf of authenticated users. If exploited, a CSRF attack can have damaging consequences like funds transfer, password change, and data deletion.

The Anatomy of a  CSRF ATTACK

CSRF ATTACKS pose a severe threat to cybersecurity and online privacy. To protect yourself, you must understand How CSRF Attacks Exploit Trust & Work and by taking Proactive Steps to Shield Your Web by Stopping these Attacks. This article also explains one of the Real-World Examples of a CSRF Attack, “The British Airways Hack of 2018”.

Staying vigilant and guarding your data is critical in today's connected world.

How CSRF Attacks Exploit Trusts & Enable Malicious Actions?

Shielding Your Web: How to Stop CSRF Attacks?

CSRF attacks work by tricking users into clicking a link or submitting a form on a website they use frequently. The link or form contains a request to act on another website or app where the user is already authenticated. Because the user is logged in, the malicious request is processed as if the user intentionally performed that action.

For example, say a user is logged into their bank app on their phone. An attacker could plant a link on another trusted site that contains a fund transfer request for the user’s bank account. If the user clicks the link, the request is processed because they are already logged in, allowing the attacker to steal money.

When you log into an app, it gives your browser a token to identify you. The app trusts that any requests using that token come from you. But a hacker can steal that token and use it to submit commands as if they came from you!

  • Say you have a banking app. A hacker could steal your token and use it to transfer money from your account without you even knowing.
  • Or with a social media app, they could post status updates or share private info as if it came from you.

The scary part is these attacks often don't require your password. The hacker just needs that single token to wreak havoc.

Shielding Your Web: How to Stop CSRF Attacks?

To effectively prevent CSRF attacks, there are several techniques you can implement.

  • Employ a Synchronizer Token Pattern: 

This involves generating a random token associated with a user's session and embedding it in all forms and links. When a request is submitted, the token is validated to ensure it matches the user's session. If not, the request is rejected.

  • Require Verification for Sensitive Actions: 

Any requests that modify data or perform sensitive actions require an additional verification step, such as a captcha or SMS authentication code. This helps prevent automated CSRF attacks.

  • Use the Same-Origin Policy: 

This policy prevents code from one origin from accessing properties of a target from another source. By enforcing this policy, you ensure that other domains cannot trigger actions on your domain.

  • Require POST Requests: 

Only allow state-changing requests like form submissions to use the POST method. GET requests should never modify data. This makes CSRF attacks more difficult since attackers cannot create a simple link to trigger the action.

  • Add a CSRF token to forms and Validate on the Server: 

Add a random token associated with a user's session to all forms. When the form is submitted, check that the CSRF token matches the user's session. If not, reject the request. This ensures that only requests from your domain can be submitted.

By implementing a combination of these techniques, you can effectively mitigate the risk of CSRF attacks against your application. Staying up-to-date with the latest web application security standards will also help keep your users safe.

A Real-World Example of a CSRF Attack

The British Airways Hack

2018 A malicious CSRF attack against British Airways resulted in the compromising of about 380,000 user accounts. Due to a flaw on BA's website, hackers were able to acquire credit card details and other private and financial data. Customers were duped into visiting a link that looked authentic but sent login requests using credentials that were already stored, giving hackers access to their accounts.

To prevent similar attacks, BA now implements stronger countermeasures such as synchronizer tokens, IP address checks, and CAPTCHA verifications on their login forms. They also recommend customers use unique passwords for different sites and enable two-factor authentication when available.

The BA hack serves as a reminder of the importance of proactive security strategies and constant vigilance. Even large companies with strong cyber defenses can be vulnerable to CSRF attacks. By prioritizing user security and following recommended precautions, both companies and customers can help mitigate the risk of CSRF attempts.

Frequently Asked Questions (FAQs)

What is a CSRF (Cross-Site Request Forgery) attack, and how does it affect mobile apps?

A CSRF (Cross-Site Request Forgery) attack is like someone impersonating you to perform actions on your behalf without your consent. In the context of mobile apps, imagine you are using a banking app on your phone. If an attacker tricks your app into making a transaction on another website without your knowledge, that would be a CSRF attack. It is similar to someone using your identity to perform actions you didn't intend or authorize.

It can enable unauthorized actions, manipulate data, bypass security measures, facilitate session hijacking, and contribute to impersonation and social engineering tactics.

What are the common vulnerabilities in mobile apps that make them susceptible to CSRF attacks?

Inadequate input validation, lack of CSRF tokens or anti-CSRF measures, and improper session management are common vulnerabilities that can expose mobile apps to CSRF attacks.

What are the best practices for preventing CSRF attacks in mobile app development?

Implementing CSRF tokens, employing strict input validation, utilizing secure session management techniques, and employing appropriate security frameworks can help mitigate CSRF vulnerabilities in mobile apps.

Are there any specific libraries or frameworks that mobile app developers can use to prevent CSRF attacks?

Yes, there are frameworks and libraries available that provide built-in protection against CSRF attacks. For example, OWASP CSRF Protector, Django CSRF protection, and Spring Security for Java are popular options.


CSRF attacks are a serious threat to web applications and the data they handle. So, if you are concerned about the security of your web application? Protect your users and their data by implementing industry-leading security measures. Contact Appknox today to fortify your application against CSRF attacks and other emerging threats. Ensure the safety and trust of your users while delivering outstanding digital experiences.

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