GraphQL Authorization Misconfiguration

GraphQL Authorization Misconfiguration

Risk: potentially

Description

A GraphQL Authorization Misconfiguration is a critical security vulnerability where a GraphQL API fails to consistently and comprehensively enforce access controls across its operations and data models. This oversight allows unauthorized users to access, modify, or delete information beyond their intended permissions, potentially compromising the entire system's security. Key characteristics of this vulnerability include inconsistent access controls, where different queries or mutations for similar data have varying levels of authorization checks, an overly permissive schema that exposes sensitive fields or operations without proper restrictions and a lack of depth-limited queries, resulting in no mechanisms to prevent resource-intensive or overly nested queries.

Implications

1. Unauthorized Data Access and Manipulation:
2. Attackers can retrieve sensitive information like personal user data, financial records, or proprietary business information.

3. Malicious users may alter or delete critical data, affecting system integrity and user trust.

4. Potential Privilege Escalation:

5. Exploiting misconfigured queries or mutations, attackers might gain administrative privileges.

6. Lateral movement within the system becomes possible, allowing access to other restricted areas.

7. Compromised System Integrity:

8. The reliability and accuracy of the entire dataset come into question.

9. Compliance violations may occur, especially concerning data protection regulations like GDPR or CCPA.

10. Data Exfiltration:

11. Large-scale data theft becomes feasible through carefully crafted queries.

12. Competitive intelligence or user databases could be extracted without detection.

13. Reputational Damage:

14. Public disclosure of such vulnerabilities can lead to loss of user trust and potential legal consequences.

Code Example

Python

  class UserType(DjangoObjectType):
    class Meta:
      model = User
      fields = ("id", "username", "email")

  class OrganizationType(DjangoObjectType):
    class Meta:
      model = Organization
      fields = ("id", "name", "users")

  class Query(graphene.ObjectType):
  all_users = graphene.List(UserType)
  organization = graphene.Field(OrganizationType, id=graphene.ID(required=True))

  def resolve_all_users(self, info):
    user = info.context.user
    if not user.is_authenticated:
      raise graphene.GraphQLError("Authentication required")
    return User.objects.all()

  def resolve_organization(self, info, id):
    try:
      org = Organization.objects.get(id=id)
    except Organization.DoesNotExist:
      raise graphene.GraphQLError("Organization not found")

    return org

In this example, note that even though the Users Query implements access control, the Organization Query does not. Since the Organization Query exposes the nested users attribute, an attacker can use it to access information that was denied when queried directly.

Query Examples:

# Secure query
query {
  allUsers {
    id
    username
    email
  }
}

# Vulnerable query
query {
  organization(id: "123") {
    id
    name
    users {
      id
      username
      email
    }
  }
}

Recommendation

Best Practices for Mitigation

1. Implement Consistent Server-Side Authorization:
2. Use middleware or decorators to enforce access controls uniformly.

3. Example:

   @require_permission('admin')
   def resolve_sensitive_data(self, info):
       # Only admins can access this resolver
       pass
   

4. Utilize Field-Level Permissions:

5. Define and enforce access controls at the field level.

6. Example using graphene-django:

   class UserType(DjangoObjectType):
       class Meta:
           model = User
           fields = ('id', 'username', 'email')
   
       @staticmethod
       def resolve_email(parent, info):
           if info.context.user.has_permission('view_email'):
               return parent.email
           return None
   

7. Use Custom Scalars for Sensitive Data:

8. Implement custom scalar types with built-in authorization checks.

9. Disable or Limit Introspection:

10. In production environments, disable introspection or limit it to authenticated and authorized users only.

11. Regular Security Audits and Scans:

12. Conduct thorough reviews of your GraphQL schema, resolvers, and access control mechanisms.

By addressing these root causes and implementing robust authorization mechanisms, developers can significantly reduce the risk of GraphQL Authorization Misconfigurations and create more secure GraphQL APIs.

Links

• Exploiting a broken access control vulnerability on GraphQL (Vaadata Blog)

Standards

• CCPA:
  • CCPA_1798_150
• CWE_TOP_25:
  • CWE_862
• OWASP_ASVS_L3:
  • V1_2_4
  • V4_1_3
  • V13_4_1
  • V13_4_2
• SOC2_CONTROLS:
  • CC_6_3