Arbitrary file ownership change via passAsFile race
Published Jun 27, 2025 · Updated Jun 27, 2025
A race condition in Nix before 2.24.15, 2.26.4, 2.28.4, and 2.29.1 allows local users to change arbitrary file ownership. Nix writes attacker-controlled passAsFile content to a .attr file, closes it, and then follows its replaceable pathname during a privileged chown. Exploitation requires building an untrusted derivation and winning a filesystem race; the resulting UID and GID change can support root escalation when chained with other flaws.
Summary
What happened
A race condition in Nix before 2.24.15, 2.26.4, 2.28.4, and 2.29.1 allows local users to change arbitrary file ownership. Nix writes attacker-controlled passAsFile content to a .attr file, closes it, and then follows its replaceable pathname during a privileged chown. Exploitation requires building an untrusted derivation and winning a filesystem race; the resulting UID and GID change can support root escalation when chained with other flaws.
The record
- CVE
- CVE-2025-52993
- Published
- Jun 27, 2025
- Updated
- Jun 27, 2025
- Vendor
- NixOS
- Product
- Nix
- Classifications
- CWE-362, T1222.002
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 27, 2025CVE publishedPublication date reported by the CVE source.
- Jun 27, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <2.24.15
- Affected versionversion=2.25.0 <2.26.4
- Affected versionversion=2.27.0 <2.28.4
- Affected versionversion=2.29.0 <2.29.1
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Snyk NixOS privilege-escalation proof of conceptfunctional · demonstrated
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Technologies
Your stack
See the directory against your own environment.
Your stack
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