AnyDesk ID Enumeration & Info Disclosure

AnyDesk clients are identified by 9-10 digit numeric IDs. The relay infrastructure leaks information about any ID during the connection handshake, before authentication. The target gets no notification.

All you need is an AnyDesk installation.

The internal IP leak is the worst part it exposes the target's network topology to anyone who knows their ID.

AnyDesk IDs are short numeric values (9-10 digits) with no secret component. They're guessable you don't need to know a target's ID to find valid ones. The relay tells you whether any given ID exists or not, creating an oracle: try random numbers, keep the ones that return a fingerprint, discard the rest.

At ~250ms per lookup, an attacker can validate thousands of IDs per hour. The ID space is large (~10 billion) but AnyDesk has 500M+ downloads, so a significant portion of the range is allocated. There's no rate limiting on the relay side.

1. Send a connection request to the relay for a target ID
2. Relay responds with status, fingerprint, IP, relay before auth
3. Target sees nothing
4. Parse ad.trace where AnyDesk logs the response

Relay response time: ~250ms.

anynet.any_socket - Client-ID: <target> (FPR: <fingerprint>).
anynet.any_socket - Logged in from <public-ip>:<port> on relay <relay-id>.
anynet.connection_mgr - Making a new connection to client <full-fingerprint>.
anynet.punch_connector - -> Spawning: <lan-ip>:7070
anynet.punch_connector - -> Spawning: <docker-ip>:7070
anynet.punch_connector - -> Spawning: <link-local-ip>:7070

{
  "timestamp": "2026-08-16T14:28:37.407584+00:00",
  "local_id": "<lab-machine-1>",
  "total_probed": 1,
  "valid_count": 1,
  "invalid_count": 0,
  "online_count": 1,
  "ip_leaked_count": 1,
  "results": [
    {
      "target_id": "<lab-machine-2>",
      "valid": true,
      "online": true,
      "client_id": "<lab-machine-2>",
      "fingerprint": "<redacted-fpr>",
      "source_ip": "<redacted-public-ip>:<port>",
      "relay_id": "<relay-id>",
      "remote_os": null,
      "remote_version": null,
      "status_text": null
    }
  ]
}

Requires AnyDesk installed. On Linux, needs an X display.

python3 anydesk_id_enum.py info
python3 anydesk_id_enum.py probe --ids <your-lab-id>
python3 anydesk_id_enum.py probe --ids <your-lab-id> --wait 10 -o results.json

# from SSH
DISPLAY=:1 python3 anydesk_id_enum.py probe --ids <your-lab-id>

• Linux (AnyDesk 8.0.4)
• Windows (hidden window mode)

• AnyDesk ACL / whitelist
• Enterprise namespace (custom IDs)
• Firewall AnyDesk relay traffic when not in use
• Disable the service when not needed
• Monitor ad.trace for recon

For authorized security research only. Don't enumerate IDs you don't own. All testing done on researcher-owned lab machines.

• 2026-08-16: Discovered, documented, and published
• This is a design-level issue in the relay protocol, not a code bug