Security readout for executives and security teams
Plain-English summary
Butter versions before 1.5 contain a high-severity JPNS kernel error. The public record says affected users should update to the Trinity kernel and that no workaround exists. The issue requires local access with low privileges, so urgency depends on where Butter is installed and who can log in there.
Executive priority
Handle as a high-priority remediation item where Butter is deployed. It is not presented as remotely wormable, but the scored impact is severe once a low-privileged local attacker has access.
Technical view
CVE-2021-39230 is a CWE-20 input validation issue in FrankEnderman Butter before 1.5. CVSS 3.1 is 8.8 with local attack vector, low complexity, low privileges, no user interaction, changed scope, and high confidentiality, integrity, and availability impact.
Likely exposure
Exposure appears limited to systems running FrankEnderman Butter versions earlier than 1.5. The CVSS vector indicates an attacker needs local access and some privileges; internet-exposed unauthenticated exploitation is not supported by the provided sources.
Exploitation context
The source bundle does not show CISA KEV listing or cited evidence of active exploitation. Public details are sparse and do not describe exploit mechanics. Treat this as a high-impact local vulnerability until affected deployments are ruled out or upgraded.
Researcher notes
Evidence is limited to the CVE record, GitHub advisory, and commit reference. The advisory names the JPNS kernel error and Trinity kernel recommendation, but does not provide detailed root cause, exploitability boundaries, or compensating controls.
Mitigation direction
- Inventory systems for FrankEnderman Butter installations before version 1.5.
- Update affected Butter deployments to the Trinity kernel path recommended by the vendor.
- Prioritize upgrades on shared, privileged, or sensitive systems.
- If upgrade is not possible, check vendor guidance; sources state no workaround exists.
- Remove Butter from systems where it is unnecessary and cannot be updated.
Validation and detection
- Confirm deployed Butter versions are 1.5 or later where the product is present.
- Verify updated systems use the Trinity kernel, not the discontinued JPNS kernel.
- Review the GitHub advisory and linked commit for vendor-specific remediation context.
- Record any remaining Butter versions below 1.5 as accepted or unresolved risk.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-20: Exact CWE lookup
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Open ATT&CK lookupCVE-2021-39230 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 8.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H26Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
8.8HighVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/FrankEnderman/Butter/security/advisories/GHSA-4538-4g86-xf6jCVE reference · x_refsource_CONFIRM
- https://github.com/FrankEnderman/Butter/commit/a4fd717e848306f04f2823ea5f617e4da9f5bbdbCVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Improper Input Validation
Improper Input Validation represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.