CVE-2026-102130 in Email Protection Gateway
Summary
by MITRE • 10/01/2026
Kiteworks Email Protection Gateway did not sufficiently validate the content of an uploaded backup, and allowed an administrator to influence how the application loaded it. An authenticated administrator could potentially use this to execute arbitrary code on the gateway as the underlying service 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 input validation and access control mechanisms within the backup restoration functionality. This flaw stems from insufficient sanitization of uploaded archive files, specifically allowing an authenticated administrator to manipulate the contents or structure of the backup file during the loading process. By exploiting this lack of rigorous validation, an attacker with administrative privileges can inject malicious payloads that are subsequently executed by the underlying service account running on the gateway server. The core technical issue lies in the application's trust model, which assumes that files uploaded and processed by administrators are inherently safe, thereby bypassing necessary security checks for path traversal, command injection, or deserialization attacks depending on how the backup is parsed internally.
From a classification perspective, this vulnerability aligns with CWE-94 Improper Control of Generation of Code (Code Injection) and potentially CWE-20 Improper Input Validation if the issue involves malformed data structures leading to unexpected execution paths. The ability for an authenticated user to influence application behavior through crafted input is characteristic of insecure deserialization or command injection flaws where the system fails to distinguish between legitimate configuration data and executable code. This misconfiguration allows the attacker to escalate their privileges from a standard administrative role, which may have limited scope, to full control over the underlying operating system via the service account permissions associated with the gateway process.
The operational impact of this vulnerability is severe, as it grants an authenticated administrator complete remote code execution capabilities on the target server. Since the code executes under the context of the application's service account, which often possesses elevated privileges necessary for network operations and file system access, the attacker can compromise not only the Kiteworks Email Protection Gateway itself but also any other systems accessible from that network segment or via lateral movement techniques. This could lead to data exfiltration, modification of email filtering rules to bypass security controls, installation of persistent backdoors, or use of the gateway as a pivot point for further attacks against internal infrastructure. The presence of this flaw undermines the integrity and confidentiality guarantees provided by the email protection service.
Mitigation strategies should focus on immediate patching if an update is available from Kiteworks that addresses the input validation logic in the backup restoration module. In the interim, administrators should restrict access to the backup management interface to only those users who absolutely require it, applying the principle of least privilege. Additionally, implementing strict file type restrictions and validating archive contents against a whitelist of expected structures can help prevent exploitation until a permanent fix is deployed. Network segmentation should also be reviewed to ensure that compromise of this gateway does not provide unrestricted access to critical internal assets, thereby limiting the blast radius in case of successful exploitation. Regular auditing of administrative actions and monitoring for unusual process executions originating from the service account are recommended defensive measures to detect potential abuse attempts early.