flaskpaste/documentation/security-testing-status.md

Security Testing Status

Tracking security testing progress and remaining tasks.

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Completed Testing

Local Fuzzer (tests/fuzz/run_fuzz.py)

Phase	Tests	Status
Reconnaissance	25 endpoints probed	PASS
Input Fuzzing	Binary, unicode, size limits	PASS
Injection Attacks	SQLi, XSS, SSTI, command injection	PASS
Auth/Authz	Header spoofing, privilege escalation	PASS
Business Logic	Burn-after-read, expiry, dedup	PASS
Cryptography	PoW token replay, timing	PASS

Production Fuzzer (mymx.me/paste)

Phase	Tests	Status
Content Fuzzing	Null bytes, unicode, 50KB, control chars	PASS
Injection Testing	SQLi, SSTI, XSS, command, path traversal	PASS
Header Injection	Host override, XFF chains, SQLi in headers	PASS
Path Fuzzing	Traversal, URL encoding, long paths	PASS
MIME Detection	GIF+JS, PNG+HTML, PDF+HTML polyglots	PASS

MIME Detection (Polyglot Attacks)

Attack Vector	Payload	Result
PNG + HTML	Magic bytes + script tag	Served as image/png
GIF + JavaScript	GIF89a + JS comment trick	Served as image/gif
PDF + ZIP	PDF header + ZIP trailer	Served as application/pdf
SVG + Script	XML with embedded script	Served as text/plain
JPEG + PHP	JFIF + PHP code	Served as image/jpeg

Race Condition Testing

Test	Method	Result
Burn-after-read bypass	HEAD then GET	SAFE - HEAD triggers deletion

Verified via server logs: Burn-after-read paste deleted via HEAD: <id>

Timing Attack Analysis

Tested authentication endpoints for timing oracle vulnerabilities (2025-12-25):

Endpoint	Test	Variance	Result
Password verification	Correct vs Wrong	2.3%	SAFE
Password verification	Correct vs None	2.1%	SAFE
Paste existence	Valid vs Invalid ID	Expected	OK (DB lookup)
Auth header	Valid vs Invalid format	Expected	OK (DB lookup)

Password verification uses PBKDF2 with 600,000 iterations (~900ms constant-time). No password oracle vulnerability - timing variance within acceptable bounds.

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Remaining Tasks

MIME Detection - Additional Formats

Tested on production (2025-12-25):

[x] WebP (image/webp)                 PASS
[x] TIFF-LE (image/tiff)              PASS
[x] TIFF-BE (image/tiff)              PASS
[x] BMP (image/bmp)                   PASS
[x] ICO (image/x-icon)                PASS
[x] WebM (video/webm)                 PASS
[x] MP4 (video/mp4)                   PASS
[x] MP3 (audio/mpeg)                  PASS
[x] MP3-ID3 (audio/mpeg)              PASS
[x] FLAC (audio/flac)                 PASS
[x] OGG (audio/ogg)                   PASS
[x] 7z (application/x-7z-compressed)  PASS
[x] RAR (application/vnd.rar)         PASS
[x] XZ (application/x-xz)             PASS
[x] BZ2 (application/x-bzip2)         PASS
[x] WASM (application/wasm)           PASS
[x] MachO-32 (application/x-mach-binary) PASS
[x] MachO-64 (application/x-mach-binary) PASS

Fallback to text/plain (safe default):
[~] MOV  - ftyp offset varies
[~] CAB  - Signature not implemented
[~] DEB  - Signature not implemented
[~] AR   - Signature not implemented

Fixed (2025-12-25):
[x] RPM  - Added signature (0xEDABEEDB)
[x] AVI  - Fixed RIFF subtype detection
[x] WAV  - Fixed RIFF subtype detection

Known issues:
[!] JavaClass - Detected as Mach-O (0xCAFEBABE collision, unfixable)

Not tested (no signature defined):
[ ] AVIF, HEIC, MKV, TAR, DMG, ISO, DOCX/XLSX/PPTX, ODF

Fuzzing Improvements

[ ] Add --target option to run_fuzz.py for external testing
[ ] Implement adaptive rate limiting in production fuzzer
[ ] Add hypothesis property-based tests for MIME detection
[ ] Create polyglot generator for automated MIME confusion testing
[x] Add timing attack tests for authentication endpoints

Penetration Testing (from PENTEST_PLAN.md)

[x] Race condition: Burn-after-read via HEAD then GET (SAFE)
[x] Race condition: Content hash deduplication counter (SAFE - locked)
[x] DoS: Memory exhaustion via unique IP rate limits (FIXED)
[x] DoS: Anti-flood list growth under load (SAFE - bounded)
[x] CLI: Clipboard command injection validation (SAFE)
[x] CLI: Certificate file permission exposure (SAFE - 0o600)

CLI Security Audit (2025-12-26)

Check	Status
Trusted clipboard path validation	PASS
PATH injection prevention	PASS
Subprocess safety (no shell=True)	PASS
Config permission warnings	PASS
Key file permissions (0o600)	PASS
Symlink attacks	LOW RISK

Memory Exhaustion Tests (2025-12-26)

Component	Protection	Status
Anti-flood list	ANTIFLOOD_MAX_ENTRIES (10000)	PASS
Rate limit dict	RATE_LIMIT_MAX_ENTRIES (10000)	PASS
Lookup rate limit	LOOKUP_RATE_LIMIT_MAX_ENTRIES (10000)	FIXED
Content dedup	Database + PoW	PASS
Concurrent access	Thread-safe with locks	PASS

Documentation

[ ] Add remaining MIME test results to security assessment
[ ] Document rate limiting behavior under attack
[ ] Create threat model diagram
[ ] Add security headers audit to CI pipeline

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Test Commands

# Local fuzzer (starts isolated server)
./venv/bin/python tests/fuzz/run_fuzz.py --verbose

# Quick smoke test
./venv/bin/python tests/fuzz/run_fuzz.py --quick

# Specific phases only
./venv/bin/python tests/fuzz/run_fuzz.py --phases 1,2,3

# Hypothesis tests (via pytest)
./venv/bin/pytest tests/test_fuzz.py -v

# Production fuzzer (rate limited)
python /tmp/prod_fuzz.py

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Security Controls Verified

Control	Implementation	Verified
X-Content-Type-Options	nosniff	Yes
Content-Security-Policy	default-src 'none'	Yes
X-Frame-Options	DENY	Yes
Magic byte detection	First 16 bytes, 45 signatures	Yes
Input sanitization	Werkzeug header handling	Yes
SQL injection prevention	SQLAlchemy parameterized queries	Yes
SSTI prevention	No user content in templates	Yes
Path traversal prevention	ID validation regex	Yes
Constant-time password check	PBKDF2 600k iterations	Yes
Burn-after-read race condition	HEAD triggers deletion	Yes
RIFF container detection	Subtype check (WEBP/AVI/WAVE)	Yes
Clipboard command injection	Trusted path validation	Yes
Memory exhaustion prevention	Max entries on all dicts	Yes
Race condition protection	Threading locks on counters	Yes

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Notes

• Production testing requires rate limit awareness (1.5s+ delay)
• X-SSL-Client-SHA1 spoofing requires TRUSTED_PROXY_SECRET in production
• /metrics endpoint intentionally exposed for Prometheus
• Hypothesis tests use Flask test client (in-memory, not network)