Nix is a package manager for Linux and other Unix systems that makes package management reliable and reproducible. A build process has access to and can change the permissions of the build directory. After creating a setuid binary in a globally accessible location, a malicious local user can assume the permissions of a Nix daemon worker and hijack all future builds.

This issue was patched in version(s) 2.23.1, 2.22.2, 2.21.3, 2.20.7, 2.19.5 and 2.18.4.