CVE-2018-9190 in FortiClient
Summary
by MITRE
A null pointer dereference vulnerability in Fortinet FortiClientWindows 6.0.2 and earlier allows attacker to cause a denial of service via the NDIS miniport driver.
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Analysis
by VulDB Data Team • 05/12/2022
The vulnerability identified as CVE-2018-9190 represents a critical null pointer dereference flaw within the Fortinet FortiClient Windows 6.0.2 and earlier versions. This issue specifically affects the NDIS miniport driver component of the FortiClient software, which serves as a network driver interface crucial for establishing and maintaining secure network connections. The vulnerability stems from inadequate input validation and error handling within the driver's memory management routines, creating a scenario where malicious actors can manipulate driver behavior through crafted input sequences.
The technical exploitation of this vulnerability occurs when the NDIS miniport driver receives malformed or unexpected input data that triggers a null pointer dereference condition. This type of flaw falls under the Common Weakness Enumeration category CWE-476, which specifically addresses null pointer dereference vulnerabilities. When the driver encounters a null pointer during execution, it attempts to access memory at address zero, causing an immediate system crash or unexpected termination. The NDIS miniport driver operates at a privileged kernel level within the Windows operating system, making this vulnerability particularly dangerous as it can lead to complete system instability and denial of service conditions.
The operational impact of CVE-2018-9190 extends beyond simple service disruption to potentially compromise the entire network security infrastructure. Organizations relying on FortiClient for endpoint protection face significant risk when this vulnerability is exploited, as it can render the security client ineffective and potentially provide attackers with opportunities to escalate privileges or bypass other security controls. The vulnerability affects systems running FortiClient Windows versions up to 6.0.2, which were widely deployed in enterprise environments, creating a substantial attack surface. According to MITRE ATT&CK framework, this vulnerability could be leveraged as part of a broader attack chain under the technique T1499 - Endpoint Termination, where adversaries seek to disrupt system operations and maintain persistence by compromising critical security components.
Mitigation strategies for this vulnerability require immediate patching of affected FortiClient installations to version 6.0.3 or later, which includes the necessary code fixes to properly validate input parameters and prevent null pointer dereference conditions. System administrators should implement comprehensive monitoring to detect potential exploitation attempts and establish automated patch management processes to prevent similar vulnerabilities from remaining unaddressed. Additionally, network segmentation and access controls should be reinforced to limit the potential impact of any successful exploitation attempts, while security teams should conduct thorough vulnerability assessments to identify other potential null pointer dereference issues within the network infrastructure and endpoint security solutions.