Nix is a package manager for Linux and other Unix systems. A bug in the fix for CVE-2024-27297 allowed for arbitrary overwrites of files writable by the Nix process orchestrating the builds (typically the Nix daemon running as root in multi-user installations) by following symlinks during fixed-output derivation output registration. This affects sandboxed Linux builds - sandboxed macOS builds are unaffected. The location of the temporary output used for the output copy was located inside the build chroot. A symlink, pointing to an arbitrary location in the filesystem, could be created by the derivation builder at that path. During output registration, the Nix process (running in the host mount namespace) would follow that symlink and overwrite the destination with the derivation's output contents. In multi-user installations, this allows all users able to submit builds to the Nix daemon (allowed-users - defaulting to all users) to gain root privileges by modifying sensitive files. This vulnerability is fixed in 2.34.5, 2.33.4, 2.32.7, 2.31.4, 2.30.4, 2.29.3, and 2.28.6.
CVSS Score
9.0
EPSS Score
0.0
Published
2026-04-08
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.
CVSS Score
9.0
EPSS Score
0.004
Published
2024-09-10
Nix is a package manager for Linux and other Unix systems. A fixed-output derivations on Linux can send file descriptors to files in the Nix store to another program running on the host (or another fixed-output derivation) via Unix domain sockets in the abstract namespace. This allows to modify the output of the derivation, after Nix has registered the path as "valid" and immutable in the Nix database. In particular, this allows the output of fixed-output derivations to be modified from their expected content. This issue has been addressed in versions 2.3.18 2.18.2 2.19.4 and 2.20.5. Users are advised to upgrade. There are no known workarounds for this vulnerability.
CVSS Score
6.3
EPSS Score
0.001
Published
2024-03-11
Nix through 2.3 allows local users to gain access to an arbitrary user's account because the parent directory of the user-profile directories is world writable.
CVSS Score
7.8
EPSS Score
0.0
Published
2019-10-09