CyberSecBulletin
CVE-2024-52867NVD status: Deferred

guix: Incorrect Default Permissions

CVE-2024-52867 is a high-severity incorrect default permissions vulnerability in guix from GNU, with a CVSS 3.1 base score of 8.1 out of 10. It can be exploited with local access to the system by an unauthenticated attacker, without any action from a user. The record lists version 5ab3c4c as the first without the flaw, so updating guix to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.23% 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. Update guix to 5ab3c4c or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
GNUguixbefore 5ab3c4c5ab3c4c

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
HighSuccess depends on conditions outside the attacker's control.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
ChangedThe attack can reach beyond the vulnerable component into other systems.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

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

Official description

guix-daemon in GNU Guix before 5ab3c4c allows privilege escalation because build outputs are accessible by local users before file metadata concerns (e.g., for setuid and setgid programs) are properly addressed. The vulnerability can be remediated within the product via certain pull, reconfigure, and restart actions. Both 5ab3c4c and 5582241 are needed to resolve the vulnerability.

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

The underlying weakness: Incorrect Default Permissions

During installation, installed file permissions are set to allow anyone to modify those files.

How developers prevent this class of flaw

  • The architecture needs to access and modification attributes for files to only those users who actually require those actions.
  • 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.

More Incorrect Default Permissions vulnerabilities (CWE-276)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Incorrect Default Permissions vulnerabilities

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