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high·Product Based Web Vulnerabilities·Updated Apr 10, 2025

CVE-2025-31489 Scanner

CVE-2025-31489 Scanner - Signature Bypass vulnerability in MinIO

Est. Time~10 seconds
Scan TypeSingle Scan
Targetsdomain, subdomain, ipv4
CostFree
3.2k
Times Used
continuous scan runs
4.7k
Continuously Checked
assets under CS
0
Vulnerabilities Found
confirmed findings
References
CVECVE-2025-31489
8.7
CVSShigh
Exploitable remotely over the internet · no authentication required.

MinIO is a High Performance Object Storage released under GNU Affero General Public License v3.0. The signature component of the authorization may be invalid, which would mean that as a client you can use any arbitrary secret to upload objects given the user already has prior WRITE permissions on the bucket. Prior knowledge of access-key, and bucket name this user might have access to - and an access-key with a WRITE permissions is necessary. However with relevant information in place, uploading random objects to buckets is trivial and easy via curl. This issue is fixed in RELEASE.2025-04-03T14-56-28Z.

Attack Vector
Network
Privileges Req.
None
User Interaction
None
Affected
minioby minio
< RELEASE.2025-04-03T14-56-28Z
Updated Aug 22, 2026View on NVD →
Detail

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

Solution Advice
  • Upgrade to the fixed software version as specified in security advisories or releases.
  • Regularly review and monitor access logs to detect unauthorized activities.
  • Limit access permissions strictly to necessary operations and ensure strict adherence to the principle of least privilege.
  • Conduct thorough testing on endpoint security to identify and mitigate similar vulnerabilities proactively.
  • Implement additional authentication and validation measures to secure data upload operations.

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