majiayu000 MCP Security Skill
This skill enforces security best practices for MCP servers and multi-agent pipelines.
5-Layer Defense Architecture
- Input Validation - Sanitize all user inputs
- Prompt Injection Prevention - Detect and block injection attempts
- SQL/NoSQL Validation - Prevent query injection
- User Context Propagation - Maintain identity through pipeline
- Authorization (RBAC/ABAC) - Enforce access controls
Prompt Injection Prevention
# Always validate and sanitize inputs
def sanitize_input(user_input: str) -> str:
# Remove potential injection patterns
# Escape special characters
# Limit length
pass
# Never directly concatenate user input into prompts
# ❌ Bad
prompt = f"Process this: {user_input}"
# ✅ Good
prompt = sanitize_input(user_input)
validated_prompt = validate_against_schema(prompt)
User Context Propagation
@dataclass
class UserContext:
user_id: str
roles: list[str]
permissions: list[str]
tenant_id: str
# Pass context through all pipeline stages
async def process_request(context: UserContext, request: Request):
# Validate permissions at each step
if not has_permission(context, "read:data"):
raise AuthorizationError()
Authorization Patterns
RBAC (Role-Based Access Control)
ROLE_PERMISSIONS = {
"admin": ["read", "write", "delete", "admin"],
"editor": ["read", "write"],
"viewer": ["read"],
}
ABAC (Attribute-Based Access Control)
def can_access(user: User, resource: Resource) -> bool:
return (
user.department == resource.department
and user.clearance >= resource.sensitivity
)
Security Checklist
- All user inputs validated and sanitized
- Prompt injection patterns detected
- SQL queries parameterized
- User context propagated through pipeline
- Authorization checked at each step
- Sensitive data encrypted
- Audit logging enabled