Nix is a package manager for Linux and other Unix systems. A bug in Nix 2.24 prior to 2.24.6 allows a substituter or malicious user to craft a NAR that, when unpacked by Nix, causes Nix to write to arbitrary file system locations to which the Nix process has access. This will be with root permissions when using the Nix daemon. This issue is fixed in Nix 2.24.6.
The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.