Authorization Flaw in MinIO Object Storage by MinIO

CVE-2025-31489

What is CVE-2025-31489?

CVE-2025-31489 is a vulnerability found in MinIO, a high-performance object storage solution designed for managing unstructured data in cloud-native environments. This vulnerability arises from an authorization flaw that allows an authenticated user with WRITE permissions to exploit the signature component of the authorization mechanism. As a result, an attacker could upload arbitrary objects to a storage bucket using any secret, provided they already possess prior knowledge of the access key and bucket name, significantly compromising the integrity and security of the stored data.

Technical Details

The vulnerability in CVE-2025-31489 stems from an issue where the signature validation does not correctly enforce the authorization for object uploads. This flaw can be easily exploited using simple commands, such as those executed through curl, making it accessible to potential attackers with minimal technical expertise. To exploit this vulnerability, an attacker needs prior WRITE permissions, the appropriate access key, and knowledge of the bucket's name, which could be obtained through various means, including social engineering or other vectors. The issue has been addressed in the MinIO release version RELEASE.2025-04-03T14-56-28Z.

Potential Impact of CVE-2025-31489

1. Data Integrity Compromise: The ability to upload arbitrary objects to a bucket can lead to unintended data overwrites or the insertion of malicious files, undermining trust in the data stored within the MinIO system.

2. Unauthorized Data Exposure: Attackers could leverage this vulnerability to upload sensitive or malicious content, potentially leading to data leakage or exposure to unauthorized users or systems.

3. Increased Attack Surface: The exploitation of this vulnerability can serve as a foothold for further attacks within the organization’s infrastructure, enabling attackers to gain deeper access and conduct more significant breaches, including data exfiltration or lateral movement.

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