Skip to main content

Insecure Access Control

Fixing Insecure Access Control​

About Insecure Access Control

What is improper access control?​

Improper access control is a vulnerability that occurs when a system does not properly restrict or enforce access to resources, such as files, directories, network resources, or application functions.

Examples of improper access control vulnerabilities include:

  • Weak access controls: When access controls are weak or easily bypassed, attackers can gain access to sensitive resources or data by exploiting security weaknesses.
  • Insufficient authorization checks: When authorization checks are insufficient, it can allow unauthorized users to access sensitive data or resources, or to perform actions that they are not authorized to do.
  • Overly permissive access: When access controls are overly permissive, they can allow users to access resources or data that they do not need, increasing the risk of data breaches or other security incidents.

Check out these videos for a high-level explanation:

  • Missing function level access control

  • Missing object level access control

What is the impact of improper access control?​

Improper access control can lead to various security threats, such as:

  • Data breaches: Improper access control can allow attackers to access sensitive data, leading to data breaches, data loss, or unauthorized access to confidential information.
  • Unauthorized access to resources: Attackers can exploit improper access control to gain unauthorized access to resources, such as servers, databases, and applications.
  • Account takeover: Attackers can use improper access control to take over user accounts and gain access to sensitive data or resources.

How to prevent improper access control?​

Here are some measures that can help ensure proper access control:

  • Strong access controls: Implement strong access controls that restrict access to sensitive resources or data based on user roles and permissions.
  • Proper user authentication and authorization: Implement proper user authentication and authorization mechanisms to ensure that only authorized users can access sensitive data and resources.
  • Input validation and sanitization: Validate and sanitize user input before using it to access internal objects or data. Use regular expressions or input filters to remove or encode any special characters that could be used to access sensitive data or resources.
  • Least privilege: Use the principle of least privilege to restrict access to resources to only what is necessary for each user role. This can help prevent attackers from gaining access to resources that they do not need to access.
  • Regular security audits: Regularly audit your system for security vulnerabilities, including improper access control vulnerabilities. Use automated tools and manual testing to identify potential issues and fix them before they can be exploited.

References​

Taxonomies​

Explanation & Prevention​

Training​

Rule-specific references:

Option A: Avoid mixing Outputcache with Authorize annotations​

Having the annotation [OutputCache] will disable the annotation [Authorize] for the requests following the first one.

  1. Go through the issues that GuardRails identified in the PR/MR.

  2. Locate the following pattern:

    [Authorize]
    public class AdminController : Controller
    {
        [OutputCache]
        public ActionResult Index()
        {
            return View();
        }
    }

  3. And modify it as shown below:

    [Authorize]
    public class AdminController : Controller
    {
        public ActionResult Index()
        {
            return View();
        }
    }

  4. Test it, ship it 🚢 and relax 🌴

Fixing Cross-Site Request Forgery​

About Cross-Site Request Forgery (CSRF)

What is Cross-Site Request Forgery?​

Cross-site request forgery (CSRF or XSRF) is a type of web application vulnerability that allows an attacker to exploit the trust relationship between a user's web browser and a web application. The vulnerability occurs when a web application doesn't adequately verify that a request comes from an authorized user, and it can allow an attacker to force an unsuspecting user to perform actions on the application without their knowledge or consent.

In a CSRF attack, an attacker will create a malicious website or email that contains a link or form that automatically sends a request to the vulnerable web application. If the victim clicks on the link or submits the form, the request will be sent to the web application, and the application will assume that it was initiated by the legitimate user.

Check out this video for a high-level explanation:

What is the impact of Cross-Site Request Forgery?​

Some potential impacts of CSRF attacks are:

  • Unauthorized actions: An attacker can use a CSRF attack to force a user to perform unauthorized actions on the vulnerable web application, such as changing their password, making unauthorized purchases, or deleting or modifying data.
  • Data breaches: An attacker can use a CSRF attack to override sensitive information from the vulnerable web application, such as login credentials.
  • Financial loss: An attacker can use a CSRF attack to force a user to make unauthorized financial transactions, resulting in financial loss for the victim.
  • Reputation damage: A successful attack exploiting a CSRF vulnerability can lead to loss of customer trust and reputational damage for the organization.
  • Regulatory violations: A successful attack exploiting a CSRF vulnerability can lead to violations of regulatory requirements, such as data protection laws.

How to prevent Cross-Site Request Forgery?​

To prevent cross-site request forgery (CSRF) attacks, web applications can implement the following measures:

  • Implement CSRF tokens: Use CSRF tokens to ensure that requests are made by legitimate users and not by attackers. The token is a unique value that is generated for each user session, and it is included in each form or link request. The server-side application checks that the token matches the user's session, and if not, it rejects the request.
  • Use HTTP Referer header validation: Validate the HTTP Referer header to ensure that requests are coming from the expected source. This can help prevent attackers from spoofing the source of a request.
  • Use anti-CSRF frameworks: Use anti-CSRF frameworks or libraries that provide built-in protection against CSRF attacks, such as Django's CSRF protection, Spring Security's CSRF protection, or the OWASP CSRFGuard library.
  • Use SameSite cookies: Use SameSite cookies to prevent CSRF attacks that leverage session hijacking through cross-site scripting (XSS) vulnerabilities.
  • Limit the use of HTTP methods: Limit the use of sensitive HTTP methods (e.g. PUT, DELETE) to authenticated and authorized users only.

References​

Taxonomies​

Explanation & Prevention​

Training​

Option A: Verify the AntiForgeryToken​

A CSRF can occur when a controller does not leverage the ValidateAntiForgeryToken annotation.

  1. Go through the issues that GuardRails identified in the PR/MR.

  2. Locate the following pattern:

    public class TestController
    {
        [HttpPost]
        public ActionResult ControllerMethod(string input)
        {
            //Do an action in the context of the logged in user
        }
    }

  3. And ensure that the AntiForgeryToken is verified

    // In your view:
    @Html.AntiForgeryToken()

    //In your controller:
    public class TestController
    {
        [HttpPost]
        [ValidateAntiForgeryToken] //Annotation added
        public ActionResult ControllerMethod(string input)
        {
            //Do an action in the context of the logged in user
        }
    }

  4. Test it

  5. Ship it 🚢 and relax 🌴

Last updated on by Stefan Streichsbier