active_attr Improper Resource Shutdown or Release vulnerability

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

7.5 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

• CVE-2021-4250: 1.18% estimated exploitation activity in the next 30 days; percentile 67.75 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

A vulnerability classified as problematic has been found in cgriego activeattr up to 0.15.3. This affects the function call of the file lib/activeattr/typecasting/booleantypecaster.rb of the component Regex Handler. The manipulation of the argument value leads to denial of service. The exploit has been disclosed to the public and may be used. Upgrading to version 0.15.4 can address this issue. The name of the patch is dab95e5843b01525444b82bd7b336ef1d79377df. It is recommended to upgrade the affected component. The associated identifier of this vulnerability is VDB-216207.

Published by the source

19 Dec 2022, 00:30 UTC

Last modified by the source

27 Jan 2023, 05:01 UTC

Source last checked

26 Oct 2026, 15:44 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-4whf-rmx5-8frv

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# Patch Next advisory brief: CVE-2021-4250

Advisory: active_attr Improper Resource Shutdown or Release vulnerability
IDs: CVE-2021-4250, GHSA-4whf-rmx5-8frv
Record: https://patchnext.com/advisories/cve-2021-4250 (revision 1, source checked 26 Oct 2026, 15:44 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: active_attr 0.15.4. A vendor fix does not mean a deployment is fixed.

## Affected components
- RubyGems active_attr: affected < 0.15.4; fixed in 0.15.4

## Suggested inspection (read-only)
- RubyGems active_attr: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on active_attr.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-4whf-rmx5-8frv (GitHub-reviewed advisory GHSA-4whf-rmx5-8frv lists affected ranges: RubyGems active_attr >=0 <0.15.4)

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