Mike Jensen 8dde70b8ca net/dns/{resolver,ipnlocal}: restrict reverse MagicDNS answers by source
A LAN-adjacent attacker can reach quad-100 on an IP-forwarding host and sweep the CGNAT range for reverse dns records to enumerate the responding node's peer set.

Restrict reverse (PTR) answers for Tailscale addresses (CGNAT plus ULA) to queries from loopback or the local peer node address only, refusing all other sources with REFUSED. Forward lookups, statics outside the Tailscale ranges, and exit-node/app-connector peer DNS are unchanged.

Fixes tailscale/corp#48229

Reported-by: @keeleysam
Change-Id: I2cf49c6cb2faa15fdde6a837b158b50cf449b26e
Signed-off-by: Mike Jensen <mikej@tailscale.com>
2026-09-22 12:30:31 -06:00
2026-09-16 10:08:11 -04:00
2026-09-03 15:37:10 -07:00
2026-07-10 17:39:16 -07:00
2026-01-27 16:15:17 -08:00
2026-06-02 10:59:29 -07:00
2026-08-28 12:47:04 -07:00
2026-09-17 16:55:23 -07:00

Tailscale

https://tailscale.com

Private WireGuard® networks made easy

Overview

This repository contains the majority of Tailscale's open source code. Notably, it includes the tailscaled daemon and the tailscale CLI tool. The tailscaled daemon runs on Linux, Windows, macOS, and to varying degrees on FreeBSD and OpenBSD. The Tailscale iOS and Android apps use this repo's code, but this repo doesn't contain the mobile GUI code.

Other Tailscale repos of note:

For background on which parts of Tailscale are open source and why, see https://tailscale.com/opensource/.

Using

We serve packages for a variety of distros and platforms at https://pkgs.tailscale.com.

Other clients

The macOS, iOS, and Windows clients use the code in this repository but additionally include small GUI wrappers. The GUI wrappers on non-open source platforms are themselves not open source.

Building

We always require the latest Go release, currently Go 1.27. (While we build releases with our Go fork, its use is not required.)

go install tailscale.com/cmd/tailscale{,d}

If you're packaging Tailscale for distribution, use build_dist.sh instead, to burn commit IDs and version info into the binaries:

./build_dist.sh tailscale.com/cmd/tailscale
./build_dist.sh tailscale.com/cmd/tailscaled

If your distro has conventions that preclude the use of build_dist.sh, please do the equivalent of what it does in your distro's way, so that bug reports contain useful version information.

Bugs

Please file any issues about this code or the hosted service on the issue tracker.

Contributing

PRs welcome! But please file bugs. Commit messages should reference bugs.

We require Developer Certificate of Origin Signed-off-by lines in commits.

See commit-messages.md (or skim git log) for our commit message style.

About Us

Tailscale is primarily developed by the people at https://github.com/orgs/tailscale/people. For other contributors, see:

WireGuard is a registered trademark of Jason A. Donenfeld.

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