---
name: security-review-cbe81ee3a710
description: "Security-focused code review with attack surface mapping and risk classification. Use when reviewing PRs for security, auditing code changes, or analyzing potential vulnerabilities. Triggers on: 'security review', 'use security mode', 'audit this', 'check for vulnerabilities', 'is this secure', 'attack surface', 'threat model', 'security check'. Read-only mode - identifies issues but doesn't fix them."
context: fork
allowed-tools: [Read, Grep, Glob, LSP]
---

# Security Review

Systematic security analysis of code changes.

## Core Approach

> "Assume the user is the attacker. Find where trust is misplaced."

## Risk Classification

| Risk Level | Triggers                                                         |
| ---------- | ---------------------------------------------------------------- |
| **HIGH**   | Auth, crypto, external calls, value transfer, validation removal |
| **MEDIUM** | Business logic, state changes, new public APIs                   |
| **LOW**    | Comments, tests, UI, logging                                     |

## Attack Surface Mapping

For each change, identify:

1. **User inputs** - request params, headers, body, URL components
2. **Database queries** - any SQL/ORM operations
3. **Auth/authz checks** - where permissions are verified
4. **External calls** - APIs, services, file system
5. **Cryptographic operations** - hashing, encryption, tokens

## Security Checklist

### Input Validation

- [ ] All user input validated before use
- [ ] Validation happens at trust boundary (not just client)
- [ ] Type coercion handled safely
- [ ] Size/length limits enforced

### Authentication/Authorization

- [ ] Auth checks present on all protected paths
- [ ] No privilege escalation paths
- [ ] Session handling is secure
- [ ] Token expiration enforced

### Data Exposure

- [ ] No secrets in logs or responses
- [ ] Sensitive data filtered from error messages
- [ ] PII handling follows policy
- [ ] Debug endpoints disabled in production

### Injection Prevention

- [ ] Parameterized queries for SQL
- [ ] Output encoding for XSS
- [ ] Command injection prevented
- [ ] Path traversal blocked

### Cryptography

- [ ] No custom crypto implementations
- [ ] Strong algorithms used (no MD5/SHA1 for security)
- [ ] Secrets not hardcoded
- [ ] Key rotation possible

## Blast Radius Analysis

For HIGH risk changes:

1. Count direct callers
2. Trace transitive dependencies
3. Identify failure modes
4. Check rollback feasibility
5. Assess data exposure scope

## Red Flags (Stop and Escalate)

- 🔴 Removed validation without replacement
- 🔴 Access control modifiers weakened
- 🔴 External calls added without error handling
- 🔴 Crypto operations changed
- 🔴 Auth bypass paths introduced
- 🔴 Secrets in source code
- 🔴 `eval()` or dynamic code execution
- 🔴 Disabled security controls (even "temporarily")

## Common Vulnerability Patterns

| Pattern                      | Look For                                      |
| ---------------------------- | --------------------------------------------- |
| **IDOR**                     | User-controlled IDs without ownership check   |
| **Mass Assignment**          | Binding request body directly to models       |
| **SSRF**                     | User-controlled URLs in server requests       |
| **Path Traversal**           | User input in file paths without sanitization |
| **Race Condition**           | Check-then-use without locking                |
| **Insecure Deserialization** | Deserializing untrusted data                  |

## Output Format

For each finding:

```markdown
**File**: `path/to/file.py:42`
**Risk**: HIGH | MEDIUM | LOW
**Category**: [Input Validation | Auth | Data Exposure | Injection | Crypto]
**Issue**: [Brief description of what's wrong]
**Evidence**: [Specific code or pattern that demonstrates the issue]
**Recommendation**: [What should be done - without implementing it]
```

## Review Summary Template

```markdown
## Security Review Summary

**Scope**: [Files/changes reviewed]
**Risk Level**: [Overall: HIGH/MEDIUM/LOW]

### Attack Surface

- Inputs: [list]
- External calls: [list]
- Auth points: [list]

### Findings

| #   | Risk | Category | File:Line  | Issue                    |
| --- | ---- | -------- | ---------- | ------------------------ |
| 1   | HIGH | Auth     | file.py:42 | Missing permission check |

### Recommendations

1. [Priority-ordered list of fixes]

### Not Reviewed

[Areas that need separate review or were out of scope]
```

## What NOT to Do

- ❌ Fix the issues (identify only)
- ❌ Assume "internal only" means safe
- ❌ Skip test files (they often reveal behavior)
- ❌ Trust comments that say "safe" or "validated elsewhere"
- ❌ Ignore configuration files

## The Security Reviewer's Creed

> "I'm not here to approve—I'm here to find what's missed."

Trust nothing. Verify everything. Document clearly.


---
Source attribution: mcouthon
Original project: https://github.com/mcouthon/agents/blob/a024cab20ec0cc9f51dea87e793fd9a5ecad8f6f/generated/claude/skills/security-review/SKILL.md
License: MIT
License information: https://opensource.org/license/mit
Original upstream instructions; downloaded from Mega AI Hub.

## Upstream license notice

MIT License

Copyright (c) 2025 Pavel Brodsky

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.



# Mega AI Hub resource metadata

Creator / publisher: mcouthon
Original project: https://github.com/mcouthon/agents/blob/a024cab20ec0cc9f51dea87e793fd9a5ecad8f6f/generated/claude/skills/security-review/SKILL.md
Attribution basis: Source repository record

Fields of work: Development & Engineering
Roles: Backend Developer, QA / Test Engineer, Security Engineer
Specialties: Testing
Tools: Grep
Country applicability: Country not specified
Classification basis: Source catalog labels
Instruction SHA-256: f91f78ddfa07a143fb2016d932ca1cfa720190cb60317569a1629c28d5fb1d85