Claude-Code-Game-Studios/.claude/skills/security-audit/SKILL.md

name, description, argument-hint, user-invocable, allowed-tools, model, agent

name	description	argument-hint	user-invocable	allowed-tools	model	agent
security-audit	Audit the game for security vulnerabilities: save tampering, cheat vectors, network exploits, data exposure, and input validation gaps. Produces a prioritised security report with remediation guidance. Run before any public release or multiplayer launch.	[full | network | save | input | quick]	true	Read, Glob, Grep, Bash, Write, Task	sonnet	security-engineer

Security Audit

Security is not optional for any shipped game. Even single-player games have save tampering vectors. Multiplayer games have cheat surfaces, data exposure risks, and denial-of-service potential. This skill systematically audits the codebase for the most common game security failures and produces a prioritised remediation plan.

Run this skill:

• Before any public release (required for the Polish → Release gate)
• Before enabling any online/multiplayer feature
• After implementing any system that reads from disk or network
• When a security-related bug is reported

Output: production/security/security-audit-[date].md

---

Phase 1: Parse Arguments and Scope

Modes:

• full — all categories (recommended before release)
• network — network/multiplayer only
• save — save file and serialization only
• input — input validation and injection only
• quick — high-severity checks only (fastest, for iterative use)
• No argument — run full

Read .claude/docs/technical-preferences.md to determine:

• Engine and language (affects which patterns to search for)
• Target platforms (affects which attack surfaces apply)
• Whether multiplayer/networking is in scope

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Phase 2: Spawn Security Engineer

Spawn security-engineer via Task. Pass:

• The audit scope/mode
• Engine and language from technical preferences
• A manifest of all source directories: src/, assets/data/, any config files

The security-engineer runs the audit across 6 categories (see Phase 3). Collect their full findings before proceeding.

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Phase 3: Audit Categories

The security-engineer evaluates each of the following. Skip categories not applicable to the project scope.

Category 1: Save File and Serialization Security

• Are save files validated before loading? (no blind deserialization)
• Are save file paths constructed from user input? (path traversal risk)
• Are save files checksummed or signed? (tamper detection)
• Does the game trust numeric values from save files without bounds checking?
• Are there any eval() or dynamic code execution calls near save loading?

Grep patterns: File.open, load, deserialize, JSON.parse, from_json, read_file — check each for validation.

Category 2: Network and Multiplayer Security (skip if single-player only)

• Is game state authoritative on the server, or does the client dictate outcomes?
• Are incoming network packets validated for size, type, and value range?
• Are player positions and state changes validated server-side?
• Is there rate limiting on any network calls?
• Are authentication tokens handled correctly (never sent in plaintext)?
• Does the game expose any debug endpoints in release builds?

Grep for: recv, receive, PacketPeer, socket, NetworkedMultiplayerPeer, rpc, rpc_id — check each call site for validation.

Category 3: Input Validation

• Are any player-supplied strings used in file paths? (path traversal)
• Are any player-supplied strings logged without sanitization? (log injection)
• Are numeric inputs (e.g., item quantities, character stats) bounds-checked before use?
• Are achievement/stat values checked before being written to any backend?

Grep for: get_input, Input.get_, input_map, user-facing text fields — check validation.

Category 4: Data Exposure

• Are any API keys, credentials, or secrets hardcoded in src/ or assets/?
• Are debug symbols or verbose error messages included in release builds?
• Does the game log sensitive player data to disk or console?
• Are any internal file paths or system information exposed to players?

Grep for: api_key, secret, password, token, private_key, DEBUG, print( in release-facing code.

Category 5: Cheat and Anti-Tamper Vectors

• Are gameplay-critical values stored only in memory, not in easily-editable files?
• Are any critical game progression flags (e.g., "has paid for DLC") validated server-side?
• Is there any protection against memory editing tools (Cheat Engine, etc.) for multiplayer?
• Are leaderboard/score submissions validated before acceptance?

Note: Client-side anti-cheat is largely unenforceable. Focus on server-side validation for anything competitive or monetised.

Category 6: Dependency and Supply Chain

• Are any third-party plugins or libraries used? List them.
• Do any plugins have known CVEs in the version being used?
• Are plugin sources verified (official marketplace, reviewed repository)?

Glob for: addons/, plugins/, third_party/, vendor/ — list all external dependencies.

---

Phase 4: Classify Findings

For each finding, assign:

Severity:

Level	Definition
CRITICAL	Remote code execution, data breach, or trivially-exploitable cheat that breaks multiplayer integrity
HIGH	Save tampering that bypasses progression, credential exposure, or server-side authority bypass
MEDIUM	Client-side cheat enablement, information disclosure, or input validation gap with limited impact
LOW	Defence-in-depth improvement — hardening that reduces attack surface but no direct exploit exists

Status: Open / Accepted Risk / Out of Scope

---

Phase 5: Generate Report

# Security Audit Report

**Date**: [date]
**Scope**: [full | network | save | input | quick]
**Engine**: [engine + version]
**Audited by**: security-engineer via /security-audit
**Files scanned**: [N source files, N config files]

---

## Executive Summary

| Severity | Count | Must Fix Before Release |
|----------|-------|------------------------|
| CRITICAL | [N] | Yes — all |
| HIGH | [N] | Yes — all |
| MEDIUM | [N] | Recommended |
| LOW | [N] | Optional |

**Release recommendation**: [CLEAR TO SHIP / FIX CRITICALS FIRST / DO NOT SHIP]

---

## CRITICAL Findings

### SEC-001: [Title]
**Category**: [Save / Network / Input / Data / Cheat / Dependency]
**File**: `[path]` line [N]
**Description**: [What the vulnerability is]
**Attack scenario**: [How a malicious user would exploit it]
**Remediation**: [Specific code change or pattern to apply]
**Effort**: [Low / Medium / High]

[repeat per finding]

---

## HIGH Findings

[same format]

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## MEDIUM Findings

[same format]

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## LOW Findings

[same format]

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## Accepted Risk

[Any findings explicitly accepted by the team with rationale]

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## Dependency Inventory

| Plugin / Library | Version | Source | Known CVEs |
|-----------------|---------|--------|------------|
| [name] | [version] | [source] | [none / CVE-XXXX-NNNN] |

---

## Remediation Priority Order

1. [SEC-NNN] — [1-line description] — Est. effort: [Low/Medium/High]
2. ...

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## Re-Audit Trigger

Run `/security-audit` again after remediating any CRITICAL or HIGH findings.
The Polish → Release gate requires this report with no open CRITICAL or HIGH items.

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Phase 6: Write Report

Present the report summary (executive summary + CRITICAL/HIGH findings only) in conversation.

Ask: "May I write the full security audit report to production/security/security-audit-[date].md?"

Write only after approval.

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Phase 7: Gate Integration

This report is a required artifact for the Polish → Release gate.

After remediating findings, re-run: /security-audit quick to confirm CRITICAL/HIGH items are resolved before running /gate-check release.

If CRITICAL findings exist:

"⛔ CRITICAL security findings must be resolved before any public release. Do not proceed to /launch-checklist until these are addressed."

If no CRITICAL/HIGH findings:

"✅ No blocking security findings. Report written to production/security/. Include this path when running /gate-check release."

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Collaborative Protocol

• Never assume a pattern is safe — flag it and let the user decide
• Accepted risk is a valid outcome — some LOW findings are acceptable trade-offs for a solo team; document the decision
• Multiplayer games have a higher bar — any HIGH finding in a multiplayer context should be treated as CRITICAL
• This is not a penetration test — this audit covers common patterns; a real pentest by a human security professional is recommended before any competitive or monetised multiplayer launch