Authorization Bypass

Category: Authentication & Authorization
Severity: High
MITRE ATT&CK Mapping: T1548 (Abuse Elevation Control Mechanism)

Description

Circumvention of access controls to perform unauthorized actions, enabling attackers to bypass authorization mechanisms and access protected resources or functionality.

Technical Details

Attack Vector

  • Authorization logic flaws
  • Access control bypass
  • Permission validation failures
  • Role-based access control bypass

Common Techniques

  • Parameter manipulation
  • HTTP method manipulation
  • Path traversal
  • Role confusion attacks

Impact

  • Unauthorized Actions: Performing actions beyond granted permissions
  • Data Access: Access to restricted data and resources
  • Privilege Escalation: Higher-level access through authorization bypass
  • System Compromise: Control over protected functionality

Detection Methods

Authorization Monitoring

  • Monitor authorization attempts
  • Track permission checks
  • Detect unauthorized access
  • Analyze access patterns

Access Control Analysis

  • Monitor role assignments
  • Track permission changes
  • Detect access anomalies
  • Analyze authorization decisions

Mitigation Strategies

Access Control Implementation

  • Implement proper authorization checks
  • Use role-based access control
  • Deploy permission validation
  • Monitor access attempts

Security Controls

  • Implement least privilege principles
  • Use authorization logging
  • Deploy access monitoring
  • Monitor permission changes

Real-World Examples

Example 1: Parameter Manipulation

def delete_user(user_id, requester_id):
    # Weak authorization check
    if requester_id == user_id:
        return delete_user_record(user_id)
    
    # Attack: manipulate user_id to match requester_id
    # delete_user(admin_user_id, admin_user_id)

Example 2: Role Confusion

def access_admin_panel(user_role):
    # Flawed role check
    if "admin" in user_role:
        return render_admin_panel()
    
    # Attack: user_role = "user_admin_viewer"
    # Contains "admin" but shouldn't grant access

Example 3: HTTP Method Bypass

@app.route('/api/users/<user_id>', methods=['GET'])
def get_user(user_id):
    # No authorization check for GET
    return get_user_data(user_id)

@app.route('/api/users/<user_id>', methods=['DELETE'])
@require_admin
def delete_user(user_id):
    # Authorization required for DELETE
    return delete_user_data(user_id)

# Attack: Use GET to bypass authorization

References & Sources

  • CyberArk - “Is your AI safe? Threat analysis of MCP”
  • AppSecEngineer - “5 Critical MCP Vulnerabilities Every Security Team Should Know”

Authorization bypass attacks exploit flaws in access control logic to gain unauthorized access to protected resources and functionality.