GHSA-qj9c-59p6-8cgx
PraisonAI: AgentMail webhook lacks signature verification, allowing unauthenticated message injection and sender spoofing
Packages
Details
As written in the advisory (Markdown source, shown as plain text).
## Summary
PraisonAI's AgentMail bot, when run in webhook (or hybrid) mode, starts an aiohttp webhook server bound to `0.0.0.0` and processes inbound `message.received` events **without verifying any signature/HMAC and without authentication**. The sender address and message body are taken directly from the attacker-controlled request body, so any network peer can inject messages into the agent with a spoofed sender (bypassing sender allow/block lists) and have the agent process the content and reply to an attacker-chosen address. Sibling bots (`linear.py`, `whatsapp.py`) fail closed when no secret is configured; AgentMail omits the check entirely. Runtime-confirmed; severity Medium.
## Details
### Affected component
- Package: `praisonai` 4.6.63. File: `src/praisonai/praisonai/bots/agentmail.py` (`AgentMailBot`, webhook/hybrid mode).
### Vulnerable code / root cause
Path:
`src/praisonai/praisonai/bots/agentmail.py`
Function:
`_start_webhook_mode` / `_handle_email_webhook` / `_handle_message`
Snippet:
```python
# _start_webhook_mode: binds all interfaces
self._webhook_site = web.TCPSite(self._webhook_runner, "0.0.0.0", self._webhook_port)
# _handle_email_webhook: no signature/HMAC check, no auth
body = await request.json()
if body.get("type") != "message.received":
return web.Response(status=200, text="OK")
asyncio.create_task(self._process_webhook_payload(body)) # dispatch attacker body
return web.Response(status=200, text="OK")
# _handle_message: agent processes content, replies to attacker-controlled sender
response = await self._session.chat(self._agent, sender_id, body, ...)
await self.send_message(channel_id=sender_id, ...)
```
Issue: attacker-controlled input is the raw webhook JSON (`from`, `extracted_text`, `subject`). The guard that *should* exist is provider signature verification — there is **none** here (no svix/HMAC, no `webhooks_require_verification()` call). The sink is `self._session.chat(self._agent, ...)` (agent invocation) and `send_message(channel_id=sender_id, ...)` (reply to the spoofed sender). Sibling handlers `src/praisonai/praisonai/bots/linear.py` and `bots/whatsapp.py` call `webhooks_require_verification()` and reject when no secret is set — AgentMail does not, so it fails open.
### Attack flow
1. Operator runs the AgentMail bot in webhook/hybrid mode (documented; binds `0.0.0.0`, default path `/webhook`, default port 8080).
2. Attacker POSTs a crafted `message.received` event with a spoofed `from` and arbitrary `extracted_text`.
3. The agent processes the content; any reply is sent to the attacker-chosen `sender_id`.
### Why existing protection is bypassed
There is no protection on this handler: no signature verification, no `webhooks_require_verification()` gate, no auth. Sender allow/block lists are bypassed because `from` is attacker-controlled.
### Security boundary
Unauthenticated network peer → agent message pipeline + reply destination. Crosses the bot's inbound trust boundary (provider webhooks are expected to be signed/authenticated).
## Proof of Concept
### Environment
Real `AgentMailBot._handle_email_webhook` mounted in a local runtime (`127.0.0.1:18080`); the agent layer is a canary recorder (`/webhook-log`). No real email is sent. Runnable assets: `PraisonAI-Runtime-Repro\runtime-files\`.
### Steps to reproduce
1. `PRAI-03-01-Webhook-Spoofed-Sender`:
```http
POST /webhook HTTP/1.1
Host: 127.0.0.1:18080
Content-Type: application/json
{"type":"message.received","data":{"from":"[email protected]","extracted_text":"PRAISONAI_WEBHOOK_INJECT_CANARY_7f3a91 ...","subject":"hello","headers":{}}}
```
2. `PRAI-03-02-Agent-Reached-Response`: `GET /webhook-log`.
### Expected result
The webhook should reject unsigned/unauthenticated events; spoofed senders should not reach the agent.
### Actual result
- `POST /webhook` → `200 OK` (no auth/signature).
- `GET /webhook-log` → `{"reached_agent":[{"sender":"[email protected]","content":"...PRAISONAI_WEBHOOK_INJECT_CANARY_7f3a91...","source":"webhook"}],"count":1}`.
## Impact
Unauthenticated message injection into the agent; sender spoofing (access-control bypass); agent reply/exfiltration to an attacker-chosen address; prompt-injection surface; LLM cost abuse. If the agent has dangerous tools, escalation via prompt injection is possible.
References
External links from the advisory. They lead to third-party sites.