CVE-2026-102915 in WPO365 Plugin
Summary
by MITRE • 10/06/2026
Subscriber Broken Access Control in WPO365 <= 44.1 versions.
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Analysis
by VulDB Data Team • 10/06/2026
The vulnerability identified as Subscriber Broken Access Control within the WebProtect Office 365 (WPO365) software, specifically affecting versions up to and including build 44.1, represents a critical failure in enforcing proper authorization policies for user accounts. This flaw stems from an insufficient validation of access rights when handling requests related to subscriber management operations. In secure systems, the principle of least privilege dictates that users should only have access to resources necessary for their specific role. However, in this instance, the application fails to adequately verify whether a requesting entity possesses the requisite permissions to perform actions on other subscribers or administrative functions intended for higher-privileged accounts. This misconfiguration allows an attacker who has obtained valid credentials for a lower-level subscriber account to bypass authorization checks and manipulate data or settings belonging to other users or the system administrator, effectively elevating their privileges without authentication of additional security controls.
From a technical perspective, this vulnerability is classified under CWE-269: Improper Privilege Assignment and aligns with MITRE ATT&CK technique T1078: Valid Accounts. The core issue lies in how the application processes HTTP requests or API calls associated with subscriber management. When an authenticated user attempts to modify another subscriber's profile, permissions, or subscription status, the backend logic does not strictly bind the action to the identity of the requester relative to the target resource. Instead, it may rely on client-side inputs or fail to check session tokens against a centralized access control list. This oversight enables horizontal privilege escalation, where an attacker moves laterally across accounts at their own level, and potentially vertical privilege escalation if administrative endpoints are accessible through similar flawed logic paths. The absence of robust server-side validation means that any authenticated user can exploit this gap by crafting specific requests to alter configurations they should not be able to touch.
The operational impact of this broken access control is severe for organizations relying on WPO365 for their email and collaboration security infrastructure. An attacker exploiting this vulnerability could gain unauthorized visibility into sensitive communications, modify spam filtering rules to allow malicious payloads through, or disable security features such as multi-factor authentication enforcement for other users. This compromises the confidentiality, integrity, and availability of organizational data. Furthermore, because WPO365 often acts as a gateway between external email traffic and internal Exchange servers, compromising subscriber accounts can serve as an initial foothold for more sophisticated attacks like business email compromise or ransomware deployment. The attacker could also use these elevated permissions to create backdoor accounts that persist even if the original compromised credentials are changed, leading to long-term unauthorized access within the network perimeter.
Mitigation strategies must prioritize immediate remediation through software updates and rigorous configuration reviews. Organizations running WPO365 versions 44.1 or earlier should immediately upgrade to a patched version released by the vendor that addresses these authorization checks. Until an update is applied, administrators should implement strict role-based access control policies at the network level, ensuring that only trusted IP ranges can interact with administrative interfaces if possible. Additionally, enabling comprehensive logging and monitoring for subscriber management activities can help detect anomalous behavior indicative of exploitation attempts. Security teams should also enforce strong password policies and multi-factor authentication to reduce the likelihood of credential theft, which is often a prerequisite for exploiting broken access controls. Regular audits of user permissions and removal of unnecessary privileges will further minimize the attack surface associated with this vulnerability type.