CVE-2025-11156 in Netskope
Summary
by MITRE • 11/28/2025
Netskope was notified about a potential gap in its agent (NS Client) on Windows systems. If this gap is successfully exploited, a local, authenticated user with Administrator privileges can improperly load the driver as a generic kernel service. This triggers the flaw, causing a system crash (Blue-Screen-of-Death) and resulting in a Denial of Service (DoS) for the affected machine.
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Analysis
by VulDB Data Team • 11/28/2025
The vulnerability identified as CVE-2025-11156 represents a critical flaw in Netskope's NS Client agent implementation on Windows operating systems. This security gap specifically affects the driver loading mechanism within the client software, creating an improper privilege escalation vector that could be exploited by malicious actors. The vulnerability stems from inadequate validation during the kernel service loading process, which allows for unauthorized manipulation of system resources through legitimate administrative access. The flaw exists within the Windows kernel-mode driver interface where proper access controls and validation checks are insufficiently implemented.
The technical exploitation of this vulnerability requires a local attacker who already possesses Administrator privileges on the target system. This prerequisite significantly reduces the attack surface but does not eliminate the risk entirely, as privilege escalation often occurs through social engineering, compromised accounts, or other initial compromise vectors. The flaw manifests when the NS Client agent attempts to load a kernel driver in a manner that bypasses normal security controls, effectively allowing the malicious code to execute with kernel-level privileges. This improper driver loading mechanism creates a path where the system's security boundaries are violated, leading to the execution of unauthorized code within the kernel space.
The operational impact of this vulnerability extends beyond simple system instability, as it creates a reliable method for achieving Denial of Service conditions through system crashes. When exploited, the vulnerability triggers a Blue Screen of Death (BSOD) which results in complete system shutdown and requires manual intervention for recovery. This disruption affects business continuity and can lead to significant downtime for affected organizations, particularly those relying heavily on Netskope's security services for network monitoring and protection. The DoS condition affects not only individual machines but can potentially cascade through networked environments, especially in enterprise settings where multiple systems may be running the vulnerable NS Client agent.
Mitigation strategies for CVE-2025-11156 should prioritize immediate patch deployment from Netskope, as this represents the most effective solution to address the root cause of the vulnerability. Organizations should also implement additional monitoring for unauthorized driver loading activities and establish strict access controls to prevent unauthorized administrative access. Network segmentation and principle of least privilege should be enforced to limit the potential impact of successful exploitation. From a cybersecurity framework perspective, this vulnerability aligns with CWE-264, which addresses permissions, privileges, and access controls in software systems. The attack pattern demonstrates characteristics consistent with ATT&CK technique T1068, which involves local privilege escalation through kernel-mode exploitation. Regular security assessments and vulnerability scanning should be implemented to detect similar issues in other security software components that may be running kernel-level services. Organizations should also consider implementing endpoint detection and response solutions that can identify anomalous driver loading behaviors and alert security teams to potential exploitation attempts.