CVE-2023-38037: Active Support Possibly Discloses Locally Encrypted Files

Severity: medium (CVSS 5.5 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-01-09 · updated 2026-06-17
Weakness: CWE-732

Description

ActiveSupport::EncryptedFile writes contents that will be encrypted to a temporary file. The temporary file's permissions are defaulted to the user's current `umask` settings, meaning that it's possible for other users on the same system to read the contents of the temporary file. Attackers that have access to the file system could possibly read the contents of this temporary file while a user is editing it. All users running an affected release should either upgrade or use one of the workarounds immediately.

Affected products

Rubygems Activesupport: from 5.2.0 before 6.1.7.5; from 7.0.0 before 7.0.7.1; 5.2.0, 5.2.1, 5.2.1.1, 5.2.1.rc1, 5.2.2, 5.2.2.1 (+98) — fixed in 6.1.7.5, 7.0.7.1
rails activesupport: from >= 5.2.0 before >= 5.2.0 — fixed in >= 5.2.0

How to fix

Upgrade to a fixed version: Rubygems Activesupport 6.1.7.5, 7.0.7.1; rails activesupport >= 5.2.0. Check the vendor advisory for mitigations.

References

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