CVE-2023-28434
Description
Minio is a Multi-Cloud Object Storage framework. Prior to RELEASE.2023-03-20T20-16-18Z, an attacker can use crafted requests to bypass metadata bucket name checking and put an object into any bucket while processing `PostPolicyBucket`. To carry out this attack, the attacker requires credentials with `arn:aws:s3:::*` permission, as well as enabled Console API access. This issue has been patched in RELEASE.2023-03-20T20-16-18Z. As a workaround, enable browser API access and turn off `MINIO_BROWSER=off`.
Summary dbcve.org
MinIO versions prior to RELEASE.2023-03-20T20-16-18Z contain an authorization bypass where attackers with S3 credentials having `arn:aws:s3:::*` permission and console API access can bypass metadata bucket name validation during PostPolicyBucket processing, allowing arbitrary object writes to any bucket.
Mitigation
Primary: Upgrade MinIO to RELEASE.2023-03-20T20-16-18Z or later. Workaround (if upgrade not immediately possible): Ensure MINIO_BROWSER is not disabled (`MINIO_BROWSER=on`) to prevent the attack vector.