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CRITICAL BUG FINDINGS - ClaudeKit Blender MCP Security Audit
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SUMMARY: 15 bugs found (2 Critical, 4 High, 7+ Medium/Low)
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CRITICAL SEVERITY - IMMEDIATE REMEDIATION REQUIRED
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BUG-001: PATH TRAVERSAL VALIDATION BYPASS
Location: src/utils/validators.ts:45-51 (filePathSchema)
Risk Level: CRITICAL
Attack Vector: Double URL encoding, normalization bypass
Impact: Arbitrary file read/write outside project directory
Example: Path "..%2F..%2Fetc%2Fpasswd" passes validation if decoded later
Proposed Fix: Normalize path before validation, use path.resolve()
Fix Effort: Low (2-3 lines added)
BUG-003: UNBOUNDED BUFFER ACCUMULATION IN SOCKET CLIENT
Location: src/utils/socket-client.ts:101-147 (receiveFullResponse)
Risk Level: CRITICAL
Attack Vector: Malicious/faulty Blender addon sending infinite data
Impact: Memory exhaustion → process crash → DoS
Scenario: Response accumulates 1MB → 100MB → 1GB, OOM kill
Proposed Fix: Add MAX_BUFFER_SIZE = 50MB limit, check totalBytes
Fix Effort: Low (3-5 lines added)
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HIGH SEVERITY - FIX WITHIN ONE WEEK
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BUG-002: CACHE KEY COLLISION VIA REGEX INJECTION
Location: src/utils/cache.ts:127-143 (invalidatePattern)
Risk Level: HIGH
Attack Vector: Unescaped regex in cache.invalidatePattern()
Impact: Cache DoS (invalidate all cached values), performance degradation
Example: pattern='.*' invalidates entire cache
Proposed Fix: Escape regex special chars with pattern.replace(/[.*+?...]/g, '\\$&')
Fix Effort: Low (1 line)
BUG-004: INTEGER OVERFLOW IN RATE LIMITING
Location: src/utils/rate-limiter.ts:57-61
Risk Level: HIGH
Attack Vector: Clock skew, tokensToAdd becomes Infinity/NaN
Impact: Silent rate limit bypass under large timePassed values
Math: (timePassed / 60000) * limit can overflow → NaN → bypass
Proposed Fix: Add isFinite() check, clamp timePassed
Fix Effort: Low (2-3 lines)
BUG-005: REGEX DENIAL OF SERVICE (ReDoS) IN CODE VALIDATION
Location: src/tools/scripting.ts:17-30 (DANGEROUS_PATTERNS)
Risk Level: HIGH
Attack Vector: Loose regex with catastrophic backtracking
Impact: Code validation hangs/freezes (180s timeout exceeded)
Example: /\bopen\s*\([^)]*['"][wa]/i with pathological input
Proposed Fix: Simplify regex, bound whitespace (/\bopen\s{0,5}\(/i)
Fix Effort: Medium (rewrite 3-4 patterns)
BUG-007: CONFIGURATION VALIDATION BYPASS
Location: src/utils/config.ts:77-82 (parseEnvNumber)
Risk Level: HIGH
Attack Vector: ENV vars bypass Zod schema constraints
Impact: Invalid config accepted (port > 65535, negative limits)
Example: RATE_LIMIT_MAX_CONCURRENT=1000000 overrides schema max:50
Proposed Fix: Re-validate config after parseEnvNumber (schema already handles it)
Fix Effort: Low (verify ConfigSchema.parse is called)
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MEDIUM SEVERITY - FIX THIS MONTH
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BUG-006: CACHE TTL INTEGER OVERFLOW
Location: src/utils/cache.ts:88-92
Risk Level: MEDIUM
Attack: set(key, value, Number.MAX_SAFE_INTEGER)
Impact: Cache never expires → memory leak, stale data
Proposed Fix: Clamp ttl to max 86400 seconds (1 day), check overflow
Fix Effort: Low (2-3 lines)
BUG-008: SEARCH QUERY SCHEMA TOO PERMISSIVE
Location: src/utils/validators.ts:85-90 (searchQuerySchema)
Risk Level: MEDIUM
Attack: Injection into external API calls (PolyHaven/Sketchfab)
Impact: Depends on downstream URL encoding
Proposed Fix: URL-encode before passing to APIs, remove control chars
Fix Effort: Medium (audit all API integration points)
BUG-009: SOCKET TIMEOUT NOT RESET DURING DATA RECEIVE
Location: src/utils/socket-client.ts:32, 101-147
Risk Level: MEDIUM
Attack: Large response (50MB) takes 190s to stream, timeout at 180s
Impact: Large asset imports fail silently with "Response timeout"
Proposed Fix: Reset timeout on each data chunk: socket.setTimeout(this.timeout)
Fix Effort: Low (1 line in onData handler)
BUG-010: RATE LIMITER CLEANUP RACE CONDITION
Location: src/utils/rate-limiter.ts:212-225
Risk Level: MEDIUM
Attack: Concurrent cleanup() and checkLimit() race condition
Impact: Bucket deleted during iteration → state corruption
Proposed Fix: Add this.isCleaningUp flag, skip concurrent cleanup
Fix Effort: Low (3-4 lines)
BUG-011: filePathSchema ALLOWS DOT FILES
Location: src/utils/validators.ts:45-51
Risk Level: LOW-MEDIUM
Attack: Path ".ssh/id_rsa" passes validation
Impact: Can access hidden directories
Proposed Fix: Add .refine(path => !path.match(/^\.+/), 'Hidden files not allowed')
Fix Effort: Low (1 line)
BUG-012: DANGEROUS PATTERNS EVADE DETECTION
Location: src/tools/scripting.ts:18-30
Risk Level: MEDIUM
Attack: "os .system()" (with space), "os['system']()", indirection
Impact: Code blocking can be bypassed with minor syntax variations
Proposed Fix: Use AST parsing instead of regex, or more comprehensive patterns
Fix Effort: High (refactor to AST-based validation)
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EDGE CASES & LOW SEVERITY ISSUES
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EDGE-002: vector3Schema ACCEPTS NaN/INFINITY
Location: src/utils/validators.ts:14-18
Risk: [NaN, 0, 0] passes validation, crashes Blender
Fix: Add .finite() constraint to all number validators
EDGE-003: colorSchema ACCEPTS NaN
Location: src/utils/validators.ts:23-28
Risk: NaN comparisons always false, validation bypassed
Fix: Add .finite() to color component validators
BUG-013: tagsSchema ALLOWS EMPTY ARRAY
Location: src/utils/validators.ts:168-175
Risk: Behavioral ambiguity (is empty allowed?)
Fix: Document expected behavior or add constraint
BUG-014: base64Schema INSUFFICIENT VALIDATION
Location: src/utils/validators.ts:133-136
Risk: Invalid base64 structure accepted, decoding may fail
Fix: Add structure validation (length % 4 check)
BUG-015: CACHE HIT COUNT INTEGER OVERFLOW
Location: src/utils/cache.ts:67-68
Risk: After 2^53 hits, counter overflows (very unlikely)
Fix: Add hit count capping
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REMEDIATION PRIORITY MATRIX
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IMMEDIATE (24 HOURS):
1. BUG-001 (path traversal) - File system security
2. BUG-003 (buffer overflow) - Process crash prevention
3. BUG-004 (rate limit overflow) - Silent bypass prevention
THIS WEEK:
4. BUG-002 (cache injection) - DoS prevention
5. BUG-005 (ReDoS) - Validation hang prevention
6. BUG-007 (config bypass) - Config integrity
THIS MONTH:
7. BUG-006, BUG-008, BUG-009, BUG-010 (various issues)
8. BUG-011, BUG-012 (pattern evasion)
9. EDGE-002, EDGE-003 (NaN validation)
FUTURE WORK:
- Replace regex-based code validation with AST parsing
- Add fuzzing to CI/CD pipeline
- Conduct penetration testing on socket protocol
- Review Blender addon source code
- Audit external API integrations for injection points
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UNRESOLVED QUESTIONS AFFECTING SEVERITY
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1. Is the Blender addon trusted or untrusted?
→ If untrusted, BUG-003 (buffer) is absolutely CRITICAL
→ If trusted, it's MEDIUM priority
2. What are actual file size limits?
→ No mention of max file downloads
→ Affects BUG-009 (timeout) and BUG-003 (buffer) priority
3. Is code execution sandboxed?
→ Affects BUG-005 (ReDoS) and BUG-012 (pattern evasion) severity
→ If not sandboxed, these should be CRITICAL
4. Are external API calls URL-encoded?
→ Affects BUG-008 (search query injection) impact
→ Need audit of all API integration points
5. What's the deployment model?
→ Local-only (low risk) vs Remote-exposed (high risk)
→ Affects all injection bugs
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DETAILED REPORT LOCATION
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Full Report: researcher-02-security-validation.md (876 lines, 24KB)
- Complete vulnerability analysis with code examples
- Attack scenarios and PoC patterns
- Proposed fixes for each bug
- Edge case analysis
- Threat model considerations
- Remediation roadmap
Generated: 2025-11-30 22:54 UTC
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