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securitycritical PriorityID: owasp-api-security-top10

OWASP API Security Top 10 Guardrails & BOLA Defense

Protection against Broken Object Level Authorization (BOLA/IDOR), Broken Object Property Level Authorization, and sensitive data leakage in REST/GraphQL APIs.

Prohibited Anti-Pattern: AI relies on client-provided IDs directly without verifying tenant ownership (BOLA vulnerability).

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---
description: OWASP API Security Top 10 Guardrails & BOLA Defense - Protection against Broken Object Level Authorization (BOLA/IDOR), Broken Object Property Level Authorization, and sensitive data leakage in REST/GraphQL APIs.
globs: **/controllers/**/*.{ts,py,go}, **/routes/**/*.{ts,py,go}
alwaysApply: true
verified_by: "agentrules.org"
license: "CC-BY-4.0"
source: "https://agentrules.org/rules/owasp-api-security-top10"
---

# OWASP API Security Top 10 Guardrails & BOLA Defense

> **Severity**: CRITICAL | **Category**: security
> **Anti-Pattern Warning**: AI relies on client-provided IDs directly without verifying tenant ownership (BOLA vulnerability).

## System Constraints
You are an API security specialist implementing OWASP API Security Top 10 standards. Defend against BOLA/IDOR: never trust client-provided object IDs without verifying that the authenticated user or tenant owns the entity.

## Strict Guidelines
- Always include tenant_id or user_id in the database WHERE clause when querying single entities by ID.
- Filter serialized responses; never dump raw database models containing password hashes, MFA secrets, or internal metadata.
- Implement global rate limiting on authentication and password reset endpoints.

## Bad vs Good Implementations
### BOLA/IDOR Defense in Entity Retrieval

#### Bad Antipattern (AI Common Hallucination)
> **Why it fails**: Omitting the ownership check allows arbitrary users to view confidential documents across tenants.
```typescript
// Anti-pattern: BOLA / IDOR vulnerability
app.get("/api/documents/:id", async (req, res) => {
  // Any authenticated user can read ANY user's private document by guessing the ID!
  const doc = await db.document.findUnique({ where: { id: req.params.id } });
  return res.json(doc); 
});
```

#### Production Standard (Correct)
> **Standard**: Guarantees that database queries are constrained by the authenticated user's organization context.
```typescript
// Production Standard: Scoped tenant/user query
app.get("/api/documents/:id", async (req, res) => {
  const session = req.user;
  const doc = await db.document.findFirst({
    where: {
      id: req.params.id,
      organizationId: session.organizationId, // Enforce tenant boundary
    },
    select: { id: true, title: true, content: true, updatedAt: true }
  });

  if (!doc) return res.status(404).json({ error: "Document not found" });
  return res.json(doc);
});
```
Recommended MCP Servers (mcp-serverlist.com)

Equip agent with system tools to verify code for this stack.

OWASP ZAP Scanner MCP
Automated vulnerability scan for BOLA, SSRF, and injection flaws.
Recommended Agent Skills (askills.dev)

Ready-to-use executable skill functions tailored to this stack.

BOLA Authorization Auditor
Scan API route handlers for missing ownership predicates.
Architectural Specification & Invariant Rationale

Architectural Invariant Design: OWASP API Security Top 10 Guardrails & BOLA Defense

OWASP API Security Top 10 Guardrails & BOLA Defense defines an industrial-grade behavioral standard for security engineering. Protection against Broken Object Level Authorization (BOLA/IDOR), Broken Object Property Level Authorization, and sensitive data leakage in REST/GraphQL APIs. Modern software architectures require strict adherence to deterministic patterns to guarantee high availability, maintainability, and zero security vulnerabilities.

Framework Paradigm Shift & Drift MechanicsLLMs are trained on millions of open-source repositories containing outdated code, legacy idioms, and unpatched antipatterns. When coding assistants generate implementations for this stack, they default to common statistical tokens: AI relies on client-provided IDs directly without verifying tenant ownership (BOLA vulnerability). Without an explicit system instruction file, developers spend hours debugging silent failures.
Failure Modes & Production Blast Radius

Hazard Analysis: What Breaks Without This Rule

The following failure modes have been cataloged from hundreds of hours of production code reviews where AI assistants produced non-compliant implementations:

Failure ModeAI Symptom (The Anti-Pattern)SeverityProduction Impact & Remedy
AI Hallucination & Deprecation DriftAI relies on client-provided IDs directly without verifying tenant ownership (BOLA vulnerability).Critical
Violating this industrial standard introduces regression bugs, security risks, and unexpected runtime failures in production.
Enforce explicit behavioral system directives across all AI coding assistants in your repository.
Silent Architecture InconsistencyAI assistants produce mixed paradigms across files, creating fragmented codebase conventions.Medium
Increases cognitive load during code reviews and leads to maintenance debt across engineering teams.
Pin project conventions in .cursor/rules, CLAUDE.md, and AGENTS.md so all team agents follow identical guardrails.
Architectural Directives in Detail

Step-by-Step Production Directives

Each rule constraint below is injected into the AI agent's system prompt to establish deterministic boundaries:

1

Always include tenant_id or user_id in the database WHERE clause when querying single entities by ID.

Always include tenant_id or user_id in the database WHERE clause when querying single entities by ID.

Rationale:AI models frequently generate unconstrained code here because statistical language distributions lack project-specific architectural context. Mandating this directive ensures that generated code adheres to verified industrial production requirements.
Enforcement:Integrated into the Agent Pack rule file. When Cursor, Claude Code, or Codex processes this prompt, it applies this constraint before emitting syntax.
2

Filter serialized responses

Filter serialized responses; never dump raw database models containing password hashes, MFA secrets, or internal metadata.

Rationale:AI models frequently generate unconstrained code here because statistical language distributions lack project-specific architectural context. Mandating this directive ensures that generated code adheres to verified industrial production requirements.
Enforcement:Integrated into the Agent Pack rule file. When Cursor, Claude Code, or Codex processes this prompt, it applies this constraint before emitting syntax.
3

Implement global rate limiting on authentication and password reset endpoints.

Implement global rate limiting on authentication and password reset endpoints.

Rationale:AI models frequently generate unconstrained code here because statistical language distributions lack project-specific architectural context. Mandating this directive ensures that generated code adheres to verified industrial production requirements.
Enforcement:Integrated into the Agent Pack rule file. When Cursor, Claude Code, or Codex processes this prompt, it applies this constraint before emitting syntax.
Technical Questions & Answers

Frequently Asked Technical Questions

Common questions developers face when configuring AI coding assistants for this stack:

Q:Why is OWASP API Security Top 10 Guardrails & BOLA Defense critical for AI coding assistants?

Protection against Broken Object Level Authorization (BOLA/IDOR), Broken Object Property Level Authorization, and sensitive data leakage in REST/GraphQL APIs. Without explicit behavioral boundaries, AI coding assistants (Cursor, Claude Code, Windsurf, Codex) rely on training data averages, which frequently produce deprecated, inefficient, or vulnerable code patterns.

Q:How does adopting this rule prevent AI hallucinations?

This rule explicitly declares what the AI must avoid (AI relies on client-provided IDs directly without verifying tenant ownership (BOLA vulnerability).) and prescribes verified positive examples. Grounding the LLM with negative and positive pairs eliminates guesswork.

Q:Which AI coding environments are supported?

This specification is multi-platform compatible: Cursor (.cursor/rules/*.mdc & .cursorrules), Anthropic Claude Code (CLAUDE.md), Windsurf (.windsurfrules), Codex / Cline (AGENTS.md), and GitHub Copilot (.github/copilot-instructions.md).

Q:Can I combine this rule with other technology stacks?

Yes. Use the Interactive Stack Builder or download an Agent Pack to merge this rule with other frontend, backend, database, security, and DevOps rules without syntax collision.

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This specification is licensed under Creative Commons Attribution 4.0 International (CC BY 4.0). You are completely free to adapt and share this rule in your workspace. If citing, including in public AI benchmark datasets, or redistributing, attribution to AgentRules.org is required.

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