Scribe MCP Server

# 🔍 Security Audit Report — Reminders Overhaul **Project:** Reminders Overhaul **Auditor:** GLM **Date:** 2025-10-26 **Version:** v1.0 **Scope:** Analysis of existing reminder system and proposed enhancements --- ## Executive Summary This security audit analyzed the existing Scribe MCP reminder system (`reminders.py`, `settings.py`, `sandbox.py`) to identify security considerations for the proposed Reminders Overhaul project. The analysis reveals a well-architected system with existing security controls that will need extension for the new configuration features. **Overall Risk Rating:** LOW - **Critical Findings:** 0 - **High Risk Findings:** 0 - **Medium Risk Findings:** 1 - **Low Risk Findings:** 2 --- ## Audit Scope & Methodology ### Code Analyzed - `scribe_mcp/reminders.py` (509 lines) - Core reminder engine - `scribe_mcp/config/settings.py` (123 lines) - Configuration system - `scribe_mcp/security/sandbox.py` (325 lines) - Path sandboxing and permissions ### Methodology - Static code analysis of existing security controls - Review of configuration handling and file operations - Analysis of sandbox boundary enforcement - Evaluation of logging and audit capabilities --- ## Current Security Controls Analysis ### ✅ Strong Existing Controls **1. Path Sandboxing (`sandbox.py`)** - `PathSandbox` class enforces repository boundaries via `is_allowed()` and `sandbox_path()` - Uses `Path.resolve()` to prevent path traversal attacks - `MultiTenantSafety` provides isolation between repositories - Raises `SecurityError` for boundary violations **2. Configuration Validation (`settings.py`)** - Environment variables parsed with type checking (`_int_env()`) - JSON parsing with error handling (`_load_env_json()`) - Default values provide safe fallbacks **3. Permission System (`sandbox.py`)** - `PermissionChecker` validates operations before execution - Configurable permissions per repository - Context-aware permission checking **4. Structured Logging** - Multi-log routing system via `log_config.json` - Security-specific log available for audit events --- ## Security Findings ### FIND-R1: Configuration File Injection Potential **Risk Level:** MEDIUM **File:** `reminders.py:156-189` **Current Code Analysis:** ```python def _build_config(project: Dict[str, Any]) -> ReminderConfig: global_defaults = settings.reminder_defaults or {} project_defaults = (project.get("defaults", {}) or {}).get("reminder", {}) severity = dict(DEFAULT_SEVERITY) severity.update(global_defaults.get("severity_weights", {})) severity.update(project_defaults.get("severity_weights", {})) ``` **Issue:** The current system uses environment variables for configuration, but the proposed externalized config files introduce: - No schema validation for configuration values - No size limits for configuration files - Direct dictionary merging without input sanitization **Recommendation:** Implement JSON schema validation for externalized configuration files with size limits and type checking. ### FIND-R2: File Reading Without Sandbox Validation **Risk Level:** LOW **File:** `reminders.py:452` **Current Code Analysis:** ```python content = await asyncio.to_thread(path.read_text, encoding="utf-8") ``` **Issue:** Document files are read directly without explicit sandbox validation, though paths come from project configuration which should be safe. **Recommendation:** Add explicit sandbox validation for all file read operations, even when using configuration-derived paths. ### FIND-R3: Error Information Disclosure **Risk Level:** LOW **File:** `reminders.py:473-496` (phase detection regex) **Current Code Analysis:** ```python async def _detect_phase(project: Dict[str, Any]) -> Optional[str]: # Complex regex parsing without error handling phases = re.findall(r"##\s+Phase\s+(.+)", content) ``` **Issue:** Regex parsing errors could expose file contents through stack traces if exceptions propagate. **Recommendation:** Add proper exception handling around regex operations and file parsing. --- ## Risk Assessment for Proposed Features ### Configuration Externalization **Risk:** MEDIUM - Introduction of file-based configuration increases attack surface **Mitigation:** JSON schema validation, size limits, atomic file operations ### Hot-Reload Mechanism **Risk:** LOW-MEDIUM - File watching introduces race conditions **Mitigation:** Atomic writes, debouncing, fallback configurations ### Per-Agent Overrides **Risk:** LOW - Agent identity verification needed **Mitigation:** Use existing MCP context, validate agent names ### CLI Interface **Risk:** LOW - Additional input validation needed **Mitigation:** Use existing sandbox validation, sanitize CLI parameters --- ## Security Control Gaps ### Needed Controls for Reminders Overhaul 1. **Configuration Schema Validation** - JSON schema with size and type limits 2. **Atomic File Operations** - Prevent race conditions in hot-reload 3. **Enhanced Input Validation** - CLI parameter sanitization 4. **Configuration Audit Logging** - Log all configuration changes to security log ### Recommended Testing Strategy 1. **Negative Path Tests** - Attempt path traversal via configuration 2. **Large File Tests** - Test configuration size limits 3. **Race Condition Tests** - Concurrent config file modifications 4. **Injection Tests** - Malicious configuration values --- ## Compliance Assessment **✅ OWASP Alignment:** - Path traversal protection via sandboxing - Input validation framework (needs extension) - Security logging capabilities - Error handling improvements needed **✅ Secure Coding Practices:** - Principle of least privilege in sandbox - Defense in depth through multiple validation layers - Fail-safe defaults in configuration --- ## Implementation Priority ### Phase 1 (Critical for Reminders Overhaul) 1. **FIND-R1 Mitigation** - JSON schema validation for externalized config 2. **Configuration Audit Logging** - Log all config changes to security log 3. **Enhanced File Validation** - Sandbox validation for all file operations ### Phase 2 (Security Hardening) 1. **FIND-R2 Mitigation** - Add explicit sandbox validation to file reads 2. **FIND-R3 Mitigation** - Exception handling for parsing operations 3. **Security Test Suite** - Negative tests and penetration testing --- ## Conclusion The existing Scribe MCP reminder system demonstrates good security practices with comprehensive sandboxing and permission controls. The proposed Reminders Overhaul features can be implemented securely by extending these existing controls rather than replacing them. The medium-risk finding around configuration file validation is addressable through schema validation and proper input handling. No critical security issues were identified in the existing codebase. **Recommendation:** Proceed with Reminders Overhaul implementation while implementing the recommended security controls, particularly configuration validation and enhanced file operation safety. --- **Audit Sign-off:** - **Auditor:** GLM - **Date:** 2025-10-26 - **Files Reviewed:** 3 core files (957 lines total) - **Next Review:** Post-Phase 1 implementation