CVE-2019-3586 in Endpoint Security
Summary
by MITRE
Protection Mechanism Failure in the Firewall in McAfee Endpoint Security (ENS) 10.x prior to 10.6.1 May 2019 update allows context-dependent attackers to circumvent ENS protection where GTI flagged IP addresses are not blocked by the ENS Firewall via specially crafted malicious sites where the GTI reputation is carefully manipulated and does not correctly trigger the ENS Firewall to block the connection.
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Analysis
by VulDB Data Team • 09/19/2023
The vulnerability identified as CVE-2019-3586 represents a critical protection mechanism failure within McAfee Endpoint Security (ENS) 10.x versions prior to the 10.6.1 May 2019 update. This flaw specifically impacts the firewall component of the security solution, creating a significant bypass opportunity for attackers who can manipulate the reputation scoring system. The vulnerability stems from an improper integration between the GTI (Global Threat Intelligence) reputation service and the ENS firewall blocking mechanisms, allowing malicious traffic to flow through the security perimeter when it should have been blocked based on reputation data.
The technical flaw manifests when GTI reputation scores for IP addresses are manipulated through carefully crafted malicious websites that exploit the timing and processing differences between the reputation scoring system and the firewall enforcement mechanism. This creates a temporal window where the firewall fails to properly evaluate and block connections to IP addresses that have been flagged by GTI as malicious. The vulnerability is context-dependent, meaning that successful exploitation requires specific conditions related to how reputation data is processed and how the firewall evaluates connections in real-time. This type of flaw aligns with CWE-284 Access Control Bypass, where insufficient access control checks allow unauthorized access to resources.
The operational impact of this vulnerability is substantial as it allows attackers to bypass firewall protections that should have blocked connections to malicious IP addresses based on GTI reputation data. This creates a persistent security gap where threat actors can establish command and control communications, exfiltrate data, or deploy malware without triggering the expected firewall alerts and blocks. The vulnerability particularly affects organizations relying on McAfee ENS for endpoint protection, potentially allowing lateral movement within networks and prolonged persistence. Attackers can leverage this weakness to establish stealthy communication channels while avoiding detection by traditional firewall-based monitoring systems.
Organizations should implement immediate mitigations including applying the McAfee ENS 10.6.1 update or later versions that address this protection mechanism failure. Network administrators should also consider implementing additional monitoring of firewall logs for anomalous patterns that might indicate attempts to exploit this vulnerability. The remediation process should include verifying that GTI reputation data is properly integrated with firewall blocking rules and that the temporal synchronization between reputation updates and enforcement mechanisms is functioning correctly. Security teams should conduct comprehensive vulnerability assessments to identify any potential exploitation attempts and ensure that alternative detection mechanisms are in place to identify malicious traffic that bypasses the primary firewall protections. This vulnerability demonstrates the importance of proper integration testing between security components and highlights the risks associated with incomplete protection mechanism implementations.