MinioApplication

CVE-2021-43858

HIGH · 8.8 CVSS v3.1 Published 2021-12-27
Fix available
A fix is available. Upgrade to 2021-12-27t07-23-18z or later.
See remediation →
94/100
Remediation priority · Urgent
Remotely reachable Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
MinIO is a Kubernetes native application for cloud storage. Prior to version `RELEASE.2021-12-27T07-23-18Z`, a malicious client can hand-craft an HTTP API call that allows for updating policy for a user and gaining higher privileges. The patch in version `RELEASE.2021-12-27T07-23-18Z` changes the accepted request body type and removes the ability to apply policy changes through this API. There is a workaround for this vulnerability: Changing passwords can be disabled by adding an explicit `Deny` rule to disable the API for users.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis
How this class of weakness works · CWE-269

Privileges are granted, or fail to be dropped, incorrectly, so an action runs with more power than it should. An attacker who reaches that path inherits the excess privilege. The fix is least-privilege throughout, with explicit, checked transitions whenever privilege changes.

General guidance for the improper privilege management class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
MinioApplication
Affected:< 2021-12-27t07-23-18z

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

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

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 2021-12-27t07-23-18z or later
Fixed in 2021-12-27t07-23-18z
Vendor patch github.com →
Recommended fix High confidence

RELEASE.2021-12-27T07-23-18Z or later

  1. Upgrade MinIO to version RELEASE.2021-12-27T07-23-18Z or later
  2. After upgrade, verify the version by running `minio --version` or checking the server startup logs
  3. Confirm the vulnerability is remediated by ensuring the API no longer accepts policy changes through the affected endpoint
  4. Alternative mitigation (if upgrade is not immediately feasible): Add an explicit Deny rule in MinIO policy to disable the password/ policy change API for users
Caveat The patch removes the ability to apply policy changes through this API - verify any automation or scripts that rely on this specific API behavior

Generated from the published advisory — verify against the referenced sources before acting.

We can perform the upgrade in your staging environment and verify nothing breaks — typical engagement from $1,950. Get the upgrade done

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-43858 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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