Resource Access Control Bypass
Category: Privilege & Access Control
Severity: High
MITRE ATT&CK Mapping: T1070 (Indicator Removal on Host)
Description
Circumventing access control mechanisms to gain unauthorized access to protected resources, files, databases, and system components within MCP environments.
Technical Details
Attack Vector
- Access control implementation flaws
- Permission bypass techniques
- Resource protection weaknesses
- Authorization mechanism failures
Common Techniques
- Permission system bypass
- Access control circumvention
- Resource enumeration
- Authorization token manipulation
Impact
- Unauthorized Access: Access to protected resources and data
- Data Exposure: Exposure of sensitive information
- System Compromise: Access to critical system components
- Privacy Violation: Unauthorized access to user data
Detection Methods
Access Monitoring
- Monitor resource access patterns
- Track authorization attempts
- Detect access control violations
- Analyze permission usage
Resource Monitoring
- Monitor resource usage
- Track unauthorized access
- Detect permission bypass
- Analyze resource protection
Mitigation Strategies
Access Control
- Implement robust access controls
- Use authorization frameworks
- Deploy access monitoring
- Regular access audits
Resource Protection
- Implement resource protection
- Use encryption for sensitive data
- Deploy access logging
- Monitor resource usage
Real-World Examples
Example 1: File Access Control Bypass
# Vulnerable file access control
class FileAccessControl:
def __init__(self):
self.permissions = {
"user1": ["read"],
"user2": ["read", "write"],
"admin": ["read", "write", "delete"]
}
def check_access(self, user, file_path, action):
# Flawed access control logic
if user in self.permissions:
if action in self.permissions[user]:
return True
# Bypass: using relative paths
if "../" in file_path:
return True # Should be False
# Attacker bypasses access control
# file_path = "../../../etc/passwd"
Example 2: Database Access Control Bypass
# Vulnerable database access control
class DatabaseAccessControl:
def __init__(self):
self.user_permissions = {
"read_user": ["SELECT"],
"write_user": ["SELECT", "INSERT", "UPDATE"],
"admin": ["SELECT", "INSERT", "UPDATE", "DELETE"]
}
def execute_query(self, user, query):
# Insufficient query validation
if user in self.user_permissions:
# Should validate query against permissions
return self.db.execute(query)
# Attacker injects privileged operations
# query = "SELECT * FROM users; DROP TABLE users;"
Example 3: API Access Control Bypass
# Vulnerable API access control
class APIAccessControl:
def __init__(self):
self.protected_endpoints = [
"/admin/users",
"/admin/settings",
"/admin/logs"
]
def check_endpoint_access(self, user, endpoint):
# Flawed endpoint protection
if endpoint in self.protected_endpoints:
if user.role == "admin":
return True
return False
# Bypass: case sensitivity flaw
if endpoint.lower() in [ep.lower() for ep in self.protected_endpoints]:
return False
# Attacker bypasses with case variation
# endpoint = "/Admin/Users"
References & Sources
- Red Hat - “Model Context Protocol (MCP): Understanding security risks and controls”
- Cisco - “AI Model Context Protocol (MCP) and Security”
Related TTPs
Resource access control bypass vulnerabilities can lead to unauthorized access to sensitive data and critical system components.