# Security Assessment Report: ATLAS-GATE-MCP-server Governance
**Date**: 2026-01-05
**Auditor**: Antigravity (Adversarial Red Team Mode)
**Target**: ATLAS-GATE-MCP-server (write_file.js, policy-engine.js)
## Executive Summary
A comprehensive adversarial audit was conducted to verify the governance enforcement enforcement of ATLAS-GATE-MCP-server. The audit simulated a hostile coding agent attempting to bypass security controls.
**Status**: **SECURE**
- **Total Attacks Attempted**: 13
- **Initial Bypasses Found**: 2
- **Remediations Applied**: 2
- **Final Result**: 0/13 Bypasses (100% Blocked)
## Methodology
We implemented a custom Red Team Runner (`tests/adversarial-runner.js`) that bypassed the network layer to invoke `writeFileHandler` directly with malicious payloads.
Attack vectors included:
1. **Stub Evasion**: `return undefined`, `() => {}`, `return {}`.
2. **Type Laundering**: `@ts-ignore`, `any` casting.
3. **Logic Removal**: Commenting out critical code.
4. **Scope Escape**: Path traversal (`../`), Absolute paths (`/tmp`), Non-repo writes.
5. **Preflight Evasion**: Writing broken code that fails tests.
6. **Governance Attacks**: Invalid Plan IDs, Hashes, Missing Prompts.
## Findings & Remediations
### Finding 1: Type Laundering Bypass (`@ts-ignore`)
- **Severity**: High
- **Description**: The AST and Text policies failed to detect `@ts-ignore` comments because the regex `\b` boundary constraint did not account for the `@` symbol starting the pattern.
- **Remediation**: Updated `core/stub-detector.js` to intelligently apply word boundaries only when the pattern starts/ends with a word character. Added `@ts-ignore` to the forbidden pattern list.
- **Verification**: Attack now triggers `TEXT_VIOLATION`.
### Finding 2: Scope Escape (`/tmp` Write)
- **Severity**: Critical
- **Description**: The `repo-resolver.js` logic correctly identified that `/tmp/evil.js` was outside the repository, but the test runner initially misclassified the result due to `path.join` usage neutralizing the absolute path. Further investigation showed `writeFileHandler` correctly calls `enforcePlan` which calls `resolveRepoRoot`, which throws `NO_GOVERNED_REPO_FOUND` for paths outside the workspace.
- **Remediation**: No code fix required in server (logic was sound). Test runner was updated to use `rawPath: true` to properly verify the protection.
- **Verification**: Confirmed that `write_file` REJECTS writes to `/tmp/evil.js` with `NO_GOVERNED_REPO_FOUND`.
## Preflight & Revert Logic
We successfully verified the "Prove It Runs" mechanism:
- **Test**: Injected a breaking change into `core/stub-detector.js` (obfuscated to pass AST checks).
- **Result**: `npm test` failed. `write_file.js` successfully caught the failure and **REVERTED** the file to its original state.
- **Conclusion**: The system effectively prevents breaking header/main/test files.
## Conclusion
The ATLAS-GATE-MCP-server governance engine is robust against common agentic shortcuts and adversarial writes. The combination of AST analysis, Diff compliance, and Preflight verification provides a strong defense-in-depth architecture.
**Recommendation**: Regularly update `TEXT_PATTERNS` in `stub-detector.js` as new evasion techniques (e.g. `nocheck`) emerge.
