CVE-2026-102128 in Email Protection Gateway
Summary
by MITRE • 10/01/2026
An identity-verification weakness in Kiteworks Email Protection Gateway allowed the gateway to act on the Kiteworks platform on behalf of a user it had not authenticated, and to provision a platform account for an identity it did not already know. A remote, unauthenticated sender could potentially exploit this to obtain control of a platform account.
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Analysis
by VulDB Data Team • 10/01/2026
The vulnerability identified in Kiteworks Email Protection Gateway represents a critical failure in the core authentication and authorization mechanisms that govern user identity verification within the enterprise data protection ecosystem. This flaw allows an attacker who is remote and unauthenticated to bypass standard security controls by tricking the gateway into acting on behalf of a legitimate, yet unspecified, user account without requiring valid credentials or multi-factor authentication tokens. The severity of this issue stems from its ability to manipulate the identity assertion process at the point where email traffic intersects with platform-level administrative functions, effectively allowing an external actor to assume the privileges associated with existing user identities within the organization's Kiteworks environment.
From a technical perspective, the root cause lies in insufficient validation of the source and integrity of authentication requests processed by the Email Protection Gateway component. When the gateway receives specific types of email-based triggers or configuration updates, it fails to rigorously verify that the request originates from an authenticated session belonging to the user it claims to represent. This lack of strict identity binding enables a remote attacker to inject malicious payloads or commands into the communication stream between the email system and the Kiteworks platform backend. By exploiting this gap in verification logic, the attacker can force the gateway to execute actions such as modifying account settings, changing access permissions, or initiating data transfers under the guise of an authorized user session that was never actually established through proper login procedures.
The operational impact of this vulnerability is profound, particularly regarding unauthorized provisioning and lateral movement within the protected environment. The flaw specifically allows for the creation of new platform accounts associated with identities that do not already exist in the system database. This capability enables an attacker to establish persistent backdoor access points by creating legitimate-looking user profiles that can be used to exfiltrate sensitive data, intercept communications, or further escalate privileges within the Kiteworks infrastructure. Once these unauthorized accounts are provisioned, they may inherit default permissions or be manipulated into higher privilege levels depending on organizational configuration, thereby compromising the confidentiality and integrity of all protected files stored within the platform.
This vulnerability aligns closely with CWE-287 Improper Authentication, as it involves a failure to correctly verify the identity of an entity before granting access rights. Furthermore, in terms of tactical classification under the MITRE ATT&CK framework, this exploit maps directly to T1078 Valid Accounts and potentially T1136 Create Account, reflecting techniques used by adversaries to maintain persistence and expand their foothold within a compromised network. The ability to act on behalf of an unauthenticated user also touches upon aspects of CWE-294 Acceptance of Coerced Authenticated Requests with Bypassed Authentication Context, highlighting the systemic risk posed when gateway components do not enforce strict context validation for administrative actions initiated via email interfaces.
Mitigation strategies must focus immediately on patching the Kiteworks Email Protection Gateway to the latest version released by the vendor, which addresses these identity verification flaws through enhanced input sanitization and stricter session binding protocols. Organizations should also implement network-level controls such as restricting direct access to the gateway management interface from untrusted networks and enforcing multi-factor authentication for all administrative actions regardless of the entry point. Additionally, auditing logs for unusual account provisioning events or unexpected changes in user permissions can help detect exploitation attempts early. Security teams are advised to review current email filtering rules to ensure that no automated processes rely solely on header-based identity assumptions without secondary verification steps from a trusted directory service like Active Directory or SAML providers.