What’s Vulnerable › Vulnerabilities

CVE-2021-43858: User privilege escalation in MinIO

• Severity: medium (CVSS 6.5 v2.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 35.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-12-27 · updated 2026-06-17
• Weakness: CWE-269

Description

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.

Affected products

• minio: before 2021-12-27t07-23-18z — fixed in 2021-12-27t07-23-18z

How to fix

Upgrade to a fixed version: minio 2021-12-27t07-23-18z. Check the vendor advisory for mitigations.

References

• https://github.com/minio/minio/commit/5a96cbbeaabd0a82b0fe881378e7c21c85091abf
• https://github.com/minio/minio/pull/13976
• https://github.com/minio/minio/pull/7949
• https://github.com/minio/minio/releases/tag/RELEASE.2021-12-27T07-23-18Z
• https://github.com/minio/minio/security/advisories/GHSA-j6jc-jqqc-p6cx
• https://github.com/minio/minio/commit/5a96cbbeaabd0a82b0fe881378e7c21c85091abf
• https://github.com/minio/minio/pull/13976
• https://github.com/minio/minio/pull/7949
• https://github.com/minio/minio/releases/tag/RELEASE.2021-12-27T07-23-18Z
• https://github.com/minio/minio/security/advisories/GHSA-j6jc-jqqc-p6cx

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