CVE-2026-15710 in Endpoint DLP
Summary
by MITRE • 09/11/2026
An information leakage vulnerability exists in the Endpoint DLP component (epdlpdrv.sys) of Netskope Client for Windows prior to version R141. An internal communication channel used by the user-space hook DLL to pass messages through the kernel driver to the daemon lacked proper token-based message validation, allowing local unprivileged processes to send unauthorized queries. Additionally, a reply buffer used by the port message handler was not properly initialized before returning data, leaking residual kernel pool memory from prior allocations. A local unprivileged attacker could exploit this vulnerability to enumerate DLP configuration and feature flags, extract live session tokens, and read kernel memory fragments from other users' operations.
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Analysis
by VulDB Data Team • 09/11/2026
The Netskope Client for Windows, specifically the Endpoint Data Loss Prevention component represented by epdlpdrv.sys prior to version R141, contains a critical information leakage vulnerability stemming from inadequate security controls in its internal communication architecture. This flaw affects the interaction between user-space hook DLLs and the kernel-mode driver, which relies on an internal channel for passing messages. The core technical deficiency lies in two distinct areas: first, the absence of proper token-based message validation within this communication pathway, and second, insufficient initialization of reply buffers used by the port message handler. These oversights create a scenario where local unprivileged processes can bypass intended access restrictions and extract sensitive data that should remain isolated from non-administrative users.
The lack of robust authentication mechanisms for inter-process communication allows any process running with standard user privileges to inject unauthorized queries into the kernel driver. Without strict validation of message tokens, the system fails to verify whether the sender has the necessary permissions to request specific information or execute certain operations within the DLP subsystem. This deficiency effectively neutralizes the boundary between untrusted user-space applications and privileged kernel-mode components, enabling attackers to interact with internal services that are not designed for public access. Consequently, an attacker can enumerate detailed configuration settings of the Data Loss Prevention software as well as feature flags that dictate how security policies are enforced on the endpoint.
Beyond enumeration capabilities, the vulnerability facilitates the extraction of live session tokens and sensitive authentication credentials stored within the Netskope Client environment. By exploiting the unvalidated communication channel, a local adversary can request data structures containing active session identifiers or other cryptographic material used to maintain secure connections with cloud services. The compromise of these tokens poses a severe risk as it may allow an attacker to impersonate the legitimate user or device, potentially gaining unauthorized access to corporate resources protected by Netskope policies without triggering standard authentication challenges.
A secondary but equally dangerous aspect of this vulnerability involves improper memory management within the kernel driver's port message handler. The reply buffer allocated for returning data to requesting processes is not properly initialized before being populated with response content. This oversight leads to a classic information disclosure flaw where residual data from previous allocations remains in the memory space and is inadvertently returned alongside legitimate responses. As a result, local unprivileged attackers can read fragments of kernel pool memory belonging to other users or system operations. This leakage provides insights into the internal state of the operating system and potentially exposes sensitive data processed by other applications running on the same endpoint.
From an industry standards perspective, this vulnerability maps directly to CWE-200: Information Exposure, as it involves the unintended disclosure of information to unauthorized actors. The exploitation technique aligns with MITRE ATT&CK techniques such as T1057: Process Discovery and T1003: OS Credential Dumping, depending on whether the attacker is enumerating configuration details or extracting session tokens. Furthermore, the memory leakage aspect relates to CWE-200 in conjunction with improper input validation principles outlined in secure coding standards for kernel-mode drivers. The failure to initialize buffers also reflects a deviation from best practices regarding memory safety and zeroization of sensitive data before reuse.
The operational impact of this vulnerability is significant for organizations relying on Netskope Client for endpoint security enforcement. An attacker with local access can gain deep visibility into the security posture of the device, including which DLP rules are active and how they are configured. This intelligence gathering phase lowers the barrier for subsequent attacks by allowing adversaries to tailor their exploits against specific weaknesses in the deployment. Additionally, the theft of live session tokens could lead to account takeover or lateral movement within a network if those credentials are reused across services. The exposure of kernel memory fragments further compromises system integrity and confidentiality, potentially revealing passwords, encryption keys, or other sensitive artifacts processed by various applications.
To mitigate this vulnerability, organizations must prioritize updating the Netskope Client for Windows to version R141 or later, where these flaws have been addressed through improved access control checks and proper buffer initialization routines. Administrators should verify that all endpoints are running patched versions of the agent software as part of their regular patch management cycles. In environments where immediate updates are not feasible, restricting local user privileges and monitoring for unusual process interactions with epdlpdrv.sys can help reduce the attack surface. Implementing strict application whitelisting policies may also prevent unauthorized processes from attempting to communicate with the DLP driver components until a permanent fix is deployed.