Affected: MervinPraison PraisonAI
PraisonAI is a multi-agent teams system. Prior to 4.6.59, the WhatsApp and Linear bot webhook handlers verify HMAC signatures only when WHATSAPP_APP_SECRET or LINEAR_WEBHOOK_SECRET is configured and otherwise parse and dispatch unsigned request bodies. A remote unauthenticated client that reaches the webhook route can forge messages, comments, or agent-session events, impersonate platform users, influence agent prompts and actions, and disrupt bot processing. This issue is fixed in 4.6.59.
Affected: PyPI: praisonai
The WhatsApp and Linear bot adapters verify the inbound webhook HMAC signature only when a secret is configured. When the secret environment variable is unset — the default on a fresh install and common in development — verification is skipped entirely and the webhook body is parsed and dispatched as a genuine, trusted event. A remote, unauthenticated attacker who can reach the bot's webhook endpoint can inject arbitrary platform events.
Affected code:
WhatsApp - src/praisonai/praisonai/bots/whatsapp.py - __init__ (line 108): self._app_secret = app_secret or os.environ.get("WHATSAPP_APP_SECRET", "") -> defaults to "" - route (line 246): app.router.add_post(self._webhook_path, self._handle_webhook) -> default path "/webhook" - _handle_webhook (lines 585-595): `if self._app_secret:` gates the ENTIRE check; when falsy the body is json.loads()'d and dispatched to _process_webhook_data() with no verification.
Linear - src/praisonai/praisonai/bots/linear.py - __init__ (line 86): self._signing_secret = signing_secret or os.environ.get("LINEAR_WEBHOOK_SECRET", "") -> "" - _handle_webhook (lines 244-248): same `if self._signing_secret:` fail-open guard. - start() (lines 169-170): only logs a warning; does not fail closed.
The _verify_signature implementations themselves are correct (constant-time HMAC-SHA256); the defect is that verification is bypassed when the secret is absent.
Impact: - WhatsApp: attacker POSTs a crafted Meta Cloud API payload spoofing any sender and mes…