Full Report
S3 compatible services carry many of the same concerns as the original S3 service. This article highlights which assumptions break and what risks remain.
Analysis Summary
# Vulnerability: Security Risks and Architectural Flaws in S3-Compatible Storage (S3 Clones)
## CVE Details
- **CVE ID**: N/A (The article describes architectural risks and implementation inconsistencies rather than a single tracked CVE).
- **CVSS Score**: N/A (Varies by provider implementation).
- **CWE**:
- CWE-284: Improper Access Control
- CWE-668: Exposure of Resource to Wrong Sphere
- CWE-2 head: Improper Implementation of Security Features
## Affected Systems
- **Products**: "Neocloud" Object Storage services providing S3-compatible APIs.
- **Providers Identified**: Nebius, Crusoe, Vultr, Lambda Labs, Cloudflare (R2), DigitalOcean.
- **Configurations**: Environments using standard AWS CLI/SDKs pointed at non-AWS service endpoints.
## Vulnerability Description
The vulnerability lies in the **broken assumptions of parity** between Amazon S3 and its clones. While these services use the S3 API for convenience, they often fail to implement the robust security controls developed by AWS over two decades.
- **API Inconsistency**: Some clones return incorrect data or perform unintended actions (e.g., a `delete-bucket-policy` command resulting in the deletion of the entire bucket).
- **Access Control Gaps**: Lack of "Block Public Access" defaults, missing granular IAM policies, and reliance on project-wide access keys rather than least-privilege IAM roles.
- **Credential Scoping**: Unlike AWS, where keys are tied to specific users/roles, some clones use keys that provide full administrative access to all buckets within a project/account, increasing the blast radius of a credential leak.
## Exploitation
- **Status**: PoC available (Conceptual/Manual exploitation).
- **Complexity**: Low (Standard S3 tools like `aws-cli` can be used).
- **Attack Vector**: Network (Remote).
## Impact
- **Confidentiality**: High (Risk of public bucket exposure or unauthorized access via over-privileged keys).
- **Integrity**: High (Potential for unauthorized modification or accidental deletion due to API misinterpretation).
- **Availability**: High (Risk of data loss through unintended bucket deletion commands).
## Remediation
### Patches
As these are Cloud Service Provider (CSP) managed services, customers cannot patch the underlying infrastructure. Users must monitor provider-specific updates.
### Workarounds
- **Strict Key Management**: Avoid using primary project keys for applications; use restricted sub-keys if supported.
- **Bucket Naming**: Use long, random strings for bucket names to prevent "bucket squatting" and discovery via brute force.
- **Manual Verification**: Test every S3 API command in a non-production environment to ensure the clone responds exactly as expected before deploying automation.
## Detection
- **Indicators of Compromise**: Unexpected API error codes (e.g., 404s or 403s) where successful calls are expected, or unusual traffic to non-AWS storage endpoints (e.g., `*.nebius.cloud`, `*.vultr.com`).
- **Detection Methods**: Cloud security posture management (CSPM) tools must be configured to audit these "Neocloud" providers specifically, as standard AWS-centric tools will not see these resources.
## References
- Wiz Research Blog: hxxps://www.wiz.io/blog/s3-clones-in-the-neoclouds
- Vultr S3 Matrix: hxxps://docs.vultr.com/products/storage/object-storage/s3-compatibility-matrix
- Nebius Documentation: hxxps://docs.nebius.com/object-storage/interfaces/aws-cli