CVE-2025-14760 is a cryptographic vulnerability classified under CWE-327 (Use of a Broken or Risky Cryptographic Algorithm) found in the AWS SDK for C++, specifically in its client-side encryption library used for encrypting and decrypting records stored in Amazon S3. The root cause is a missing cryptographic key commitment mechanism when encrypted data keys (EDKs) are stored in an "instruction file" instead of the standard S3 metadata record. This omission allows an attacker with write permissions on the S3 bucket to replace or introduce a malicious EDK that decrypts to different plaintext than intended, effectively enabling data integrity violations. The vulnerability does not directly expose plaintext data (no confidentiality loss) nor does it affect availability, but it undermines the trustworthiness of encrypted data by allowing tampering undetected by the client. Exploitation requires network access and low privileges but has a high attack complexity due to the need for write access and manipulation of encryption artifacts. AWS has addressed this issue in SDK version 1.11.712 and later, recommending users upgrade to these versions to ensure cryptographic key commitment is enforced. No known exploits have been reported in the wild as of the publication date (December 17, 2025).

For European organizations, this vulnerability poses a significant risk to data integrity in cloud environments leveraging AWS SDK for C++ client-side encryption with S3 storage. Attackers with write access to S3 buckets could manipulate encrypted data keys, causing clients to decrypt altered plaintext without detection. This could lead to corrupted data, erroneous processing, or compliance violations, especially in sectors handling sensitive or regulated data such as finance, healthcare, and government. While confidentiality and availability remain intact, the integrity breach can undermine trust in cloud storage solutions and complicate incident response. Organizations relying on automated data processing or audit trails may face operational disruptions or legal consequences if tampered data is used. Given the widespread adoption of AWS services across Europe, failure to patch could expose critical infrastructure and data repositories to subtle but impactful attacks.

European organizations should immediately upgrade all deployments of AWS SDK for C++ to version 1.11.712 or later to ensure the cryptographic key commitment mechanism is properly implemented. Additionally, organizations should audit S3 bucket permissions to restrict write access strictly to trusted entities, minimizing the risk of unauthorized EDK manipulation. Implement monitoring and alerting on unusual changes to S3 instruction files and metadata to detect potential tampering attempts. Incorporate cryptographic verification steps in client applications to validate decrypted data integrity beyond relying solely on the SDK. Conduct regular security reviews of client-side encryption implementations and ensure compliance with AWS best practices for key management and access control. Finally, maintain an incident response plan that includes procedures for handling cryptographic integrity breaches in cloud storage.