Unpatched Tailscale SSH port forwarding flaws could let a hacked device reach root on other servers

Cyberdione Labs researcher Erica Windisch published lab research called Tailworm showing that Tailscale SSH port forwarding could let an already-compromised device escalate to root on other servers in a tailnet. Tailscale SSH authorizes by device rather than user credentials, and with port forwarding enabled the researcher connected the root-level Tailscale process to privileged system sockets, then used a race condition to capture a device-enrollment key and enroll a rogue server, a step blocked by Tailnet Lock. She tested Tailscale 1.104.2 and headscale 0.29.5. No CVE or fix existed at publication on October 25, no in-the-wild attacks are reported, and Tailscale is working on fixes.

Check

Write Tailscale SSH access rules as single source-to-destination pairs, disable SSH port forwarding where possible, and enable Tailnet Lock and node-key expiry.

Affected

Tailnets with broad Tailscale SSH grants and port forwarding enabled could let one compromised device escalate to root on other reachable servers, per lab research.

Fix

Tighten SSH access rules, remove unneeded port forwarding and app-connector permissions, enable Tailnet Lock, and watch for a Tailscale fix since none exists yet.