CVE-2021-28052 is a high-severity vulnerability affecting Hitachi Vantara's Hitachi Content Platform (HCP), specifically versions prior to 8.3.7 and 9.0.0 versions prior to 9.2.3. The vulnerability is classified under CWE-264, which relates to improper permissions, privileges, and access controls. In this case, the flaw allows a tenant administrator within a multi-tenant HCP environment to modify configurations belonging to another tenant without proper authorization. Additionally, even tenant users without administrative privileges can view configuration details of other tenants. This cross-tenant access breach undermines the fundamental isolation expected in multi-tenant cloud storage platforms. The vulnerability has a CVSS 3.1 base score of 7.5, indicating high severity, with the vector highlighting network attack vector (AV:N), high attack complexity (AC:H), low privileges required (PR:L), no user interaction (UI:N), unchanged scope (S:U), and high impact on confidentiality, integrity, and availability (C:H/I:H/A:H). Exploiting this vulnerability could lead to unauthorized data exposure, unauthorized configuration changes, and potential disruption of services across tenants. The issue arises from insufficient access control enforcement in the HCP's multi-tenant architecture, allowing privilege escalation and unauthorized data access across tenant boundaries. No known exploits are currently reported in the wild, but the vulnerability's nature and impact warrant prompt attention and remediation.

For European organizations using Hitachi Content Platform, this vulnerability poses significant risks. Many enterprises and service providers rely on HCP for secure, scalable object storage in multi-tenant environments. Unauthorized cross-tenant access could lead to exposure of sensitive data, including personal data protected under GDPR, resulting in regulatory penalties and reputational damage. Integrity and availability impacts could disrupt business operations, especially for organizations using HCP for critical data storage and backup. The breach of tenant isolation undermines trust in cloud services and could facilitate lateral movement by attackers within a shared infrastructure. Given the high confidentiality, integrity, and availability impacts, European organizations must prioritize patching to maintain compliance and operational security.

Organizations should immediately verify their HCP versions and upgrade to 8.3.7 or later, or 9.2.3 or later for the 9.x series, where the vulnerability is patched. Until patches are applied, restrict tenant administrator privileges strictly and audit tenant configurations for unauthorized changes. Implement network segmentation and access controls to limit administrative access to the HCP management interfaces. Enable detailed logging and monitoring of tenant configuration changes to detect suspicious activity. Conduct regular security assessments of multi-tenant environments to ensure proper isolation. Coordinate with Hitachi Vantara support for guidance on secure configuration and any available interim mitigations. Additionally, review and reinforce internal policies around privilege management and tenant separation to reduce risk exposure.