CyberSecBulletin
CVE-2025-53819NVD status: Deferred

nix: Privilege Dropping / Lowering Errors

Published Updated By the CyberSecBulletin desk

CVE-2025-53819 is a high-severity privilege dropping / lowering errors vulnerability in nix from NixOS, with a CVSS 3.1 base score of 7.9 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. Affected nix versions: = 2.30.0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.15% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of nix you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on github.com for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
NixOSnix= 2.30.0Not stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
ChangedThe attack can reach beyond the vulnerable component into other systems.
Confidentiality
LowSome restricted data can be read.
Integrity
HighData or code can be modified at will.
Availability
LowPerformance or availability is reduced.

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:H/A:L. Scored by CNA (github.com).

Official description

Nix is a package manager for Linux and other Unix systems. Builds with Nix 2.30.0 on macOS were executed with elevated privileges (root), instead of the build users. The fix was applied to Nix 2.30.1. No known workarounds are available.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Privilege Dropping / Lowering Errors

The product does not drop privileges before passing control of a resource to an actor that does not have those privileges.

How developers prevent this class of flaw

  • Compartmentalize the system to have safe areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area. Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.
  • Very carefully manage the setting, management, and handling of privileges. Explicitly manage trust zones in the software.
  • Consider following the principle of separation of privilege. Require multiple conditions to be met before permitting access to a system resource.

More Privilege Dropping / Lowering Errors vulnerabilities (CWE-271)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in nix

All nix vulnerabilities

Recent Privilege Dropping / Lowering Errors vulnerabilities

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