# Security Audit Report

**Branch**: fix/issue-28-graph-corruption-shallow-copy
**Base**: main
**Date**: 2025-11-28 11:04
**Files Analyzed**: 11 (5 source files + 2 test files + 4 docs/config)
**Lines Changed**: ~400 additions, ~80 deletions

---

## Executive Summary

This branch contains a **CRITICAL security fix** for Issue #28 (graph corruption via shallow copy) along with performance improvements for worker spawn burst protection and npm audit vulnerability fixes. The changes are **security-positive** overall.

**Verdict**: No security vulnerabilities introduced. Branch fixes existing security issues.

---

## [RED] Issues in Your Changes (BLOCKING)

**None identified.**

All changes in this branch are either security fixes or defensive improvements. No new vulnerabilities were introduced.

---

## [ORANGE] Issues in Code You Touched (Should Fix)

### MEDIUM: Optional chaining on `recordSpawn()` allows silent failure

**File**: `/workspace/delegate/src/services/handlers/worker-handler.ts:296`
**Line Type**: ADDED in this branch

```typescript
// Record spawn for settling worker tracking (accounts for lag in load average)
this.resourceMonitor.recordSpawn?.();
```

**Analysis**:
The optional chaining (`?.`) is used because `recordSpawn` was added as an optional method to the `ResourceMonitor` interface. While this is a reasonable approach for backward compatibility, it means that if someone implements a custom `ResourceMonitor` without `recordSpawn()`, the settling workers tracking silently does nothing.

**Security Impact**: LOW
- Not exploitable
- Worst case: spawn burst protection partially disabled for custom implementations

**Recommendation**: Consider making `recordSpawn()` required in the interface or adding a warning log when the method is missing:
```typescript
if (this.resourceMonitor.recordSpawn) {
  this.resourceMonitor.recordSpawn();
} else {
  this.logger.debug('ResourceMonitor does not implement recordSpawn - settling tracking disabled');
}
```

---

### LOW: `console.warn` used instead of structured logger

**File**: `/workspace/delegate/src/core/configuration.ts:139-141`
**Line Type**: ADDED in this branch

```typescript
console.warn(
  `[Delegate] Configuration validation failed, using defaults:\n${errors}`
);
```

**Analysis**:
The configuration loading happens before the logger is initialized, so `console.warn` is appropriate here. However, in production environments, console output might not be captured by log aggregation systems.

**Security Impact**: LOW
- This is actually a security improvement (no longer silently failing)
- But could miss visibility in some deployment scenarios

**Recommendation**: Acceptable as-is since logger unavailable at config load time. Consider documenting this behavior.

---

## [INFO] Pre-existing Issues Found (Not Blocking)

### INFO: `any` type in TaskEventEmitter interface

**File**: `/workspace/delegate/src/core/interfaces.ts:205`
**Line Type**: Pre-existing (not changed in this branch)

```typescript
emit(event: string, ...args: any[]): void;
```

**Analysis**:
The `any` type allows arbitrary arguments, bypassing TypeScript's type safety. This is a pre-existing issue unrelated to this PR.

**Security Impact**: LOW (type safety only, no runtime impact)

---

### INFO: Environment variable parsing accepts 0 as valid

**File**: `/workspace/delegate/src/core/configuration.ts:107-126`
**Line Type**: Pre-existing (not changed in this branch)

```typescript
if (process.env.TASK_TIMEOUT) envConfig.timeout = parseEnvNumber(process.env.TASK_TIMEOUT, 0);
```

**Analysis**:
If someone sets `TASK_TIMEOUT=0`, the check `if (process.env.TASK_TIMEOUT)` evaluates to true (string "0" is truthy), but then Zod validation will reject it since minimum is 1000ms. This behavior is correct but potentially confusing.

**Security Impact**: None (Zod validation catches invalid values)

---

## Security Fixes in This Branch

This branch **fixes** the following security issues:

### CRITICAL FIX: Graph Corruption via Shallow Copy (Issue #28)

**File**: `/workspace/delegate/src/core/dependency-graph.ts:250-255`

**Before (VULNERABLE)**:
```typescript
const tempGraph = new Map(this.graph);
```

**After (FIXED)**:
```typescript
// SECURITY FIX (Issue #28): Deep copy required to prevent graph corruption
// Shallow copy (new Map(this.graph)) only copies Map structure - Set values are REFERENCES
// When we modify temp graph's Sets, we would mutate the original graph's Sets
const tempGraph = new Map(
  Array.from(this.graph.entries()).map(([k, v]) => [k, new Set(v)])
);
```

**Impact**: 
- **Before**: Cycle detection could permanently corrupt the dependency graph
- **After**: Cycle detection is a pure read operation that cannot modify state

**Severity**: CRITICAL - Could cause unpredictable task execution order, potential deadlocks

---

### HIGH FIX: npm audit vulnerabilities resolved

**File**: `package-lock.json`

Fixed vulnerabilities:
1. **glob CLI command injection (HIGH)** - GHSA-5j98-mcp5-4vw2
   - glob 10.4.5 -> 10.5.0
2. **body-parser denial of service (MODERATE)** - GHSA-wqch-xfxh-vrr4
   - body-parser 2.2.0 -> 2.2.1
3. **vite path traversal on Windows (MODERATE)** - GHSA-93m4-6634-74q7
   - vite 7.1.9 -> 7.2.4

---

### MEDIUM FIX: Configuration validation no longer silent

**File**: `/workspace/delegate/src/core/configuration.ts:134-141`

**Before**: Configuration validation failures silently fell back to defaults
**After**: Logs warning message with specific validation errors

This helps users discover misconfigured environment variables instead of running with unexpected defaults.

---

### MEDIUM FIX: Spawn burst protection improved

**File**: `/workspace/delegate/src/implementations/resource-monitor.ts:27-31, 79-181`

**Improvement**: Added settling workers tracking to prevent spawn burst overload.

- Load average is a 1-minute rolling average that doesn't reflect recent spawns
- New `recordSpawn()` tracks workers in 15-second settling window
- Projects resource usage including workers not yet reflected in metrics
- Increased `minSpawnDelayMs` from 50ms to 1000ms for additional protection

This is a defense-in-depth improvement against fork-bomb scenarios.

---

### LOW FIX: Type safety improvement

**File**: `/workspace/delegate/src/services/handlers/worker-handler.ts:395-398`

**Before**:
```typescript
workers: readonly any[];
```

**After**:
```typescript
workers: readonly Worker[];
```

Replaces `any` type with proper `Worker` type for better type safety.

---

## Summary

| Category | CRITICAL | HIGH | MEDIUM | LOW |
|----------|----------|------|--------|-----|
| Issues in Your Changes | 0 | 0 | 0 | 0 |
| Issues in Code You Touched | 0 | 0 | 1 | 1 |
| Pre-existing Issues | 0 | 0 | 0 | 2 |
| **Security Fixes (Positive)** | 1 | 1 | 2 | 1 |

**Security Score**: 9/10

The branch fixes critical security issues without introducing new ones.

---

## Merge Recommendation

**APPROVED** - This branch is ready to merge.

**Rationale**:
- No blocking issues in changed lines
- Critical graph corruption bug fixed with proper deep copy
- npm audit vulnerabilities patched
- Improved spawn burst protection (defense in depth)
- Configuration validation now logs warnings instead of silent fallback
- Good test coverage for the fixes (3 regression tests for immutability)

---

## Final Issue Counts

- **RED** BLOCKING: 0
- **ORANGE** SHOULD-FIX: 2 (both LOW severity, non-blocking)
- **INFO** PRE-EXISTING: 2

