CVE-2026-55863

Summary

The ActionHandler.post() method in motionEye has no authentication decorator, allowing any unauthenticated attacker to trigger camera actions including snapshots, recording start/stop, and configured action scripts (PTZ controls, alarm triggers, etc.).

Vulnerability Details

File: motioneye/handlers/action.py — ActionHandler.post() line 36 CWE: CWE-862 — Missing Authorization CVSS: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N = 5.3 Medium

Vulnerable Code

class ActionHandler(BaseHandler):
    async def post(self, camera_id, action):   # ← NO @BaseHandler.auth() decorator
        camera_id = int(camera_id)
        if camera_id not in config.get_camera_ids():
            raise HTTPError(404, 'no such camera')
        ...
        if action == 'snapshot':
            await self.snapshot(camera_id)   # executed without auth
            return
        elif action == 'record_start':
            return self.record_start(camera_id)
        elif action == 'record_stop':
            return self.record_stop(camera_id)

        action_commands = config.get_action_commands(local_config)
        command = action_commands.get(action)
        ...
        self.run_command_bg(command)   # executes predefined shell scripts

Compare with other handlers that correctly require authentication:

@BaseHandler.auth(admin=True)   # ← properly protected
async def delete(self, camera_id, filename):
    ...

Steps to Reproduce

1. Deploy motionEye with at least one camera configured
2. Send unauthenticated POST:

POST /action/1/snapshot HTTP/1.1
Host: motioneye-host:8765
Content-Length: 0

3. Observe {} (HTTP 200) response — snapshot triggered without any credentials

For action scripts (lock, unlock, alarm_on, alarm_off, light_on, etc.):

POST /action/1/alarm_on HTTP/1.1
Host: motioneye-host:8765

Impact

• Unauthenticated attacker can trigger camera snapshots on demand
• Unauthenticated attacker can start/stop video recording
• If action scripts are configured by admin: attacker can trigger PTZ movement, alarm control, lighting changes — physical security bypass
• Via remote cameras: SSRF by triggering action on a remote motionEye server

Verification

Dynamically confirmed on v0.43.1 in Docker lab — POST /action/2/snapshot with no credentials returns HTTP 200 {}. Server log shows the action was processed (failed only because motion daemon was not running for the test camera, not due to an auth rejection).

Recommended Fix

class ActionHandler(BaseHandler):
    @BaseHandler.auth()   # add authentication requirement
    async def post(self, camera_id, action):
        ...