CVE-2021-21362

Bypassing readOnly policy by creating a temporary 'mc share upload' URL

MEDIUM
6.5
CVSS Score
Published: March 8, 2021 at 06:40 PM UTC
Updated: June 17, 2026 at 03:35 AM UTC
1 product affected across 1 vendorMinIO

Using minio by minio?

Get instant alerts when new vulnerabilities affect minio - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Severity
MEDIUM6.5
Exploit prediction
EPSS 1%

Description

MinIO is an open-source high performance object storage service and it is API compatible with Amazon S3 cloud storage service. In MinIO before version RELEASE.2021-03-04T00-53-13Z it is possible to bypass a readOnly policy by creating a temporary 'mc share upload' URL. Everyone is impacted who uses MinIO multi-users. This is fixed in version RELEASE.2021-03-04T00-53-13Z. As a workaround, one can disable uploads with `Content-Type: multipart/form-data` as mentioned in the S3 API RESTObjectPOST docs by using a proxy in front of MinIO.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 2021-03-04t00-53-13zv < RELEASE.2021-03-04T00-53-13Z
Affected range stops below 2021-03-04t00-53-13z, so it looks safe — our inference, not a vendor statement
Affected range stops below RELEASE.2021-03-04T00-53-13Z, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
HIGH
Availability
NONE
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-285CWE-863

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Free plan, no card