CVE-2025-31489 Scanner

MinIO is a popular high-performance object storage system used by individuals and enterprises for building scalable cloud storage infrastructure. It provides an easy-to-use interface and compatibility with Amazon S3 APIs, making it an attractive choice for developers and businesses. Many companies utilize MinIO in their private cloud environments to handle large volumes of unstructured data efficiently. It is commonly used in data centers and by organizations requiring secure, resilient, and reliable storage solutions. Its open-source nature under the GNU Affero General Public License v3.0 encourages customization and community collaboration. MinIO is designed to support cloud-native workloads, enhancing flexibility and integration with modern application ecosystems.

The detected vulnerability in MinIO involves incomplete signature validation for unsigned-trailers during uploads. It allows users with WRITE permissions to use arbitrary secrets to upload objects, deviating from expected authorization protocols. The vulnerability poses a risk by potentially allowing unauthorized users to exploit the system if they possess necessary credentials and bucket information. Such shortcomings in signature validation undermine the security model designed to protect against unauthorized data manipulation. This vulnerability highlights a critical security oversight in ensuring precise validation of signature elements in access requests. Ensuring complete and correct signature validation is essential to minimize potential exploitation risks.

Technically, the vulnerability takes advantage of how MinIO handles the authorization of uploads with unsigned-trailer content. It requires prior knowledge of the user's access key, bucket name, and the applicable Permissions for uploads. Exploiting this vulnerability involves crafting specific HTTP requests with tailored headers that bypass proper signature checks. An attacker can use tools like curl to execute such upload requests, illustrating the feasibility and ease of exploiting this flaw. The vulnerability hinges on the failure to adequately enforce signature validation for specific components through the object storage interface. Once exploited, this vulnerability allows for unauthorized data uploads to a user's storage bucket without expected validation barriers.

When exploited, this vulnerability can lead to unauthorized data uploads or modifications within the storage system, posing risks of data breaches or integrity issues. Malicious users could potentially upload harmful or fraudulent data, impacting the security posture of the organization utilizing MinIO. Unchecked data uploads might result in resource exhaustion, affecting storage performance or incurring unexpected costs. It may also undermine user trust and compliance with data protection regulations, leading to reputational damage and potential legal consequences. The ability to bypass signature checks disrupts the secure operational expectations of cloud storage environments.

REFERENCES

• https://github.com/minio/minio/pull/21103
• https://github.com/minio/minio/security/advisories/GHSA-wg47-6jq2-q2hh