CSRF (Cross-Site Request Forgery) is a kind of online security hole that lets an attacker do things on behalf of the victim. This can be done by getting the victim to click on a harmful link or by putting harmful code on a website the victim visits.
CSRF attacks can be stopped using synchronizer tokens or same-site cookies and doing enough validation and cleaning of user input on the server side. When a user sends in a form, the server checks the token’s value against the value saved in the user’s session. If the values don’t match, it could be part of a CSRF attack. Use the AntiForgeryToken utility in ASP.NET to make and check synchronizer tokens.
In Spring, you can use the csrf tag in your templates to add a synchronizer token to your forms. CSRF (Cross-Site Request Forgery) attacks are where requests sent to a server can be changed. In 2018, Ticketmaster UK said that a hacker had used a CSRF attack on the company’s website to get the personal information of up to 40,000 customers. CSRF attacks are aimed at the browser of the person being attacked. Server-side request forgery, or SSRF, is a type of online security flaw that lets an attacker send fake requests to other servers or resources from a server that is vulnerable to this flaw.
CSRF attacks can only happen when the person being attacked is logged in to the web application being attacked. Both have the potential to cause significant problems, so web developers need to be careful with them. Server-side request forgery (SSRF) is an attack vector that can be used to compromise web applications and resources. An attacker could use SSRF to take advantage of third-party APIs and do things on behalf of the victim, like send emails or post on social media. Web developers need to use a variety of security measures to protect their servers and resources.
Cross-Site Request Forgery is the full name of CSRF. It is a web security flaw that lets an attacker take over the victim’s account on an online application and do things the victim is not allowed to do.
This can be done by getting the victim to click on a harmful link or adding harmful code to a website the victim visits.
A CSRF cyber attack takes the benefit of the fact that a web application trusts a user’s browser. When a user logs in to a website and their browser saves their authentication cookie, the browser will include the cookie in future requests to the website. This means that an attacker can do things on behalf of a victim if they can get the victim to send a request to a vulnerable web application.
What Does a CSRF Attack Look Like?
A CSRF (Cross-Site Request Forgery) attack is a kind of online security hole that lets an attacker do things on behalf of the victim on a web application that the victim has not authorized. This can be done by getting the victim to click on a harmful link or by putting harmful code on a website the victim visits.
Here is a real-world example of a CSRF attack:
The attacker makes a malicious website or emails with a link to a vulnerable online application. The link has a message asking you to do something, like send money or change your password. When the victim gets the wrong website or email, he or she clicks on the link.
The request is sent to the vulnerable web application by the victim’s browser and any authentication cookies the victim has saved. Without the victim’s knowledge or permission, the web application carries out the request and does what was asked of it. To stop CSRF attacks, web developers can use “synchronizer tokens.”
You need to make a unique, unexpected token for each user session and store it in a hidden field on each website’s forms. When a user sends in a form, the server checks the token’s value against the value saved in the user’s session. If the values are the same, the request is valid and is dealt with.
The request is turned down if the values do not match because it could be part of a CSRF attack.
CSRF attacks can be stopped with the help of synchronizer tokens. It works by ensuring that every request to the server includes a unique token to the user’s session.
Since an attacker would not have the correct token, they would not be able to make a fake request.
Another way to protect against CSRF attacks is to use “same-site” cookies.
These cookies are only given to the server if the request comes from a similar kind of website that sets the cookie. Since the request does not come from the same website, an attacker could not use the cookie in a fake request.
Overall, CSRF attacks can be stopped using synchronizer tokens or same-site cookies and doing enough validation and cleaning of user input on the server side. Web developers need to be aware of these weaknesses and take steps to protect their apps and the people who use them.
How can the CSRF flaw in the most popular web frameworks be fixed?
There are many ways to protect against CSRF attacks in common web frameworks:
Tokens for synchronization: Synchronizer tokens are one of the most common ways to stop CSRF attacks. They are sometimes called “CSRF tokens” or “anti-CSRF tokens.” You need to make a unique, unexpected token for each user session and store it in a hidden field on each website’s forms. When a user sends in a form, the server checks the token’s value against the value saved in the user’s session. If the values are the same, the request is valid and is dealt with. The request is turned down if the values do not match because it could be part of a CSRF attack.
Site-to-site cookies: Another way to protect against CSRF attacks is to use “same-site” cookies.
These cookies are only given to the server if the request comes from a similar kind of website that sets the cookie. Since the request does not come from the same website, an attacker could not use the cookie in a fake request.
Validation and cleaning of input: Validation and cleaning input may also help stop CSRF attacks.
Before processing the request, check that all of the user’s input is correct and get rid of any characters or code that could be dangerous.
Here are some real-world examples of how to protect common web frameworks from CSRF attacks:
- Use the AntiForgeryToken utility in ASP.NET to make and check synchronizer tokens.
- Use the protect from forgery function in the ApplicationController to turn on CSRF protection in Ruby on Rails.
- Using the csrf token template element, you can add a synchronizer token to your forms in Django. The csrf protect decorator can protect particular views from CSRF attacks.
- In Spring, you can use the csrf tag in your templates to add a synchronizer token to your forms.
- You can also use the @CsrfViewFilter annotation to protect specific controllers from CSRF attacks.
It is important to remember that stopping CSRF attacks is only one part of keeping your online information safe. Other security measures should also be implemented, like input validation and sanitization, safe password storage, and protection against SQL injection and cross-site scripting (XSS).
Here are some examples of CSRF attacks:
Phishing Attack on Paypal: In 2006, a group of hackers started a phishing campaign to steal information from Paypal users. The attackers sent out fake emails that looked like they were from Paypal and had a link to a malicious website that looked just like the actual Paypal login page.
When people used the fake website and gave their login information, the attackers used a CSRF attack to move money from the victims’ accounts to their own accounts.
Yahoo! Mail Attack: In 2013, researchers found a Yahoo! Mail service flaw that let attackers send spam emails from Yahoo! Mail users’ accounts. The attackers took advantage of the weakness by sending spam emails to the victims’ contacts without their knowledge. This is called a CSRF attack.
In 2014, researchers found a flaw in the eBay website that let attackers change the prices of things sold on the site. Attackers used a CSRF attack to take advantage of the weakness. They lowered the prices of high-value products and bought them at a lower price.
Ticketmaster Attack: In 2018, Ticketmaster UK said that a hacker had used a CSRF attack on the company’s website to get the personal information of up to 40,000 customers. The hacker got people’s names, phone numbers, email addresses, and payment information.
These examples show what can happen when CSRF attacks occur, from losing money to having personal information stolen. Web developers need to be aware of these weaknesses and take steps to protect their apps and the people who use them.
Server-Side Request Forgery (SSRF) vs. Cross-Site Request Forgery (CSRF)
Server-side request forgery (SSRF) and cross-site request forgery are web security flaws that allow requests sent to a server to be changed (CSRF).
However, there are some crucial differences between the two:
SSRF attacks are aimed at the server, while CSRF attacks are aimed at the browser of the person being attacked.
Scope:
- SSRF attacks can be used to access resources on the server or on servers that the attacker does not have direct access to.
- CSRF attacks can only happen when the person being attacked is logged in to the web application being attacked.
Execution:
- SSRF attacks happen on the server, while CSRF attacks happen on the client or the victim’s browser.
- Checking and cleaning up user input and limiting access to some server resources can stop SSRF attacks.
- Using synchronizer tokens or same-site cookies and performing enough server-side validation and cleaning of user input can stop CSRF attacks.
Overall, both SSRF and CSRF attacks have the potential to cause significant problems, so web developers need to be careful with them. To protect against these weaknesses, it is essential to take the proper security steps and keep them up-to-date and in good shape.
Let’s look at SSRF in detail.
Server-side request forgery, or SSRF, is a type of online security flaw that lets an attacker send fake requests to other servers or resources from a server that is vulnerable to this flaw.
SSRF attacks can be used to do the following:
Access to internal resources: SSRF lets an attacker access internal resources that are usually inaccessible from the Internet, like servers behind a firewall or intranet websites.
Scanning network ranges: An attacker could use SSRF to search a network range for open ports and security holes.
Bypassing access controls: An attacker could use SSRF to get around access controls and use files or databases that they should not be able to.
(DDoS) attack: An attacker could use SSRF to send many requests to a target server as part of a distributed denial of service (DDoS) attack.
Abusing third-party APIs: An attacker could use SSRF to take advantage of third-party APIs and do things on behalf of the victim, like send emails or post on social media.
Web developers need to know about the dangers of SSRF and take steps to protect their servers and resources.
This means that user input needs to be checked and cleaned up, access to specific resources needs to be limited, and security measures must be updated regularly. Overall, server-side request forgery (SSRF) is an attack vector that can compromise web applications and resources. This can be accomplished through authentication, rate-limiting, and allowing access only to trusted sources.
Therefore, web developers must remain aware of the risks associated with SSRF attacks and make sure they have a comprehensive strategy to mitigate them. In order to prevent SSRF attacks, web developers must incorporate a variety of security measures into their applications.
