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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: Set A Proper ACL​

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

  2. Identify patterns like below and ensure that the ACL is not NULL.

    /* This is an example of bad code - the third paramer is NULL, so it creates
    a NULL ACL.  Note that Flawfinder can't detect when a
    SECURITY_DESCRIPTOR structure is manually created with a NULL value
    as the ACL; doing so would require a tool that handles C/C++
    and knows about types more that flawfinder currently does.
    Anyway, this needs to be detected: */
    SetSecurityDescriptorDacl(&sd,TRUE,NULL,FALSE);

  3. Test it

  4. Ship it 🚢 and relax 🌴

Last updated on by Stefan Streichsbier