James Tucker ff3bb58830 ssh/tailssh: validate accepted env values, deny GLIBC_TUNABLES, cap names
GLIBC_TUNABLES is parsed by glibc in root su/login environments with
AT_SECURE=0 (CVE-2023-4911 class); add it to the dangerous-env-var
denylist next to its GCONV_PATH/LOCPATH siblings.

The TERM/LANG/LC_* pairs accepted without policy (OpenSSH's default
AcceptEnv) had unvalidated values that reach root-exec'd login/su
environments, where glibc treats path-like locale names as locale-data
paths and leading dashes as its own options. Reject path- and
option-like values (and NUL, which would truncate on exec) instead of
trying to sanitize them.

Also cap accepted env var names at 256 bytes before any wildcard
matching, bounding the matcher input and the child's "su -w" allowlist;
real names are short (LOGIN_NAME_MAX).

Updates tailscale/corp#50380

Signed-off-by: James Tucker <james@tailscale.com>
2026-10-24 13:55:35 -07:00
…
…
2026-10-19 10:18:56 -07:00
…
…
…
…
…
…
…
2026-10-22 10:52:43 -04:00
…
…
2026-10-20 05:35:13 -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.

S
Description
No description provided
Readme BSD-3-Clause
207 MiB
0 Stars 1 Watchers 0 Forks
Languages
Go 96.3%
C 1.3%
TypeScript 0.8%
Shell 0.5%
Swift 0.3%
Other 0.4%