CVE-2018-6668 is a vulnerability identified in McAfee Application Control and Change Control version 7.0.1 and earlier. This vulnerability allows an attacker to bypass the whitelist enforcement mechanism implemented by these products. Specifically, the flaw enables execution bypass through simple DLL files when used with interpreters such as PowerShell. McAfee Application Control is designed to restrict execution of unauthorized applications by maintaining a whitelist of approved executables. The bypass vulnerability undermines this security control by allowing unapproved code to execute despite the whitelist restrictions. The vulnerability is classified with a CVSS v3.0 base score of 6.1, indicating a medium severity level. The vector metrics indicate that the attack requires local access (AV:L), low attack complexity (AC:L), and low privileges (PR:L), but no user interaction (UI:N). The impact primarily affects availability (A:H) with limited confidentiality impact (C:L) and no integrity impact (I:N). The vulnerability does not appear to have known exploits in the wild as of the last update. The root cause involves insufficient validation of DLL execution paths or interpreter usage, allowing attackers to leverage scripting environments like PowerShell to run unauthorized code despite whitelist policies. This can lead to denial of service or disruption of application control enforcement, potentially enabling further malicious activities on the affected system.

For European organizations, this vulnerability poses a risk to endpoint security and application control integrity. Organizations relying on McAfee Application Control to enforce strict application whitelisting may find their defenses circumvented, allowing unauthorized code execution. This could lead to service disruptions, unauthorized software running on critical systems, or a foothold for attackers to escalate privileges or move laterally within networks. The confidentiality impact is limited, but the availability impact is significant, as attackers could disrupt normal operations or disable security controls. Given the reliance on PowerShell in many Windows environments, this vulnerability could be exploited by insiders or attackers with limited access to bypass controls. European organizations in sectors with high regulatory requirements for software integrity and availability, such as finance, healthcare, and critical infrastructure, could face compliance and operational risks if this vulnerability is exploited.

Organizations should upgrade McAfee Application Control and Change Control to versions later than 7.0.1 where this vulnerability is patched. If immediate patching is not possible, administrators should restrict local user privileges to minimize the ability to execute PowerShell scripts or load unauthorized DLLs. Implementing strict PowerShell execution policies and monitoring PowerShell activity can help detect and prevent exploitation attempts. Additionally, applying application control policies that include script interpreters and DLLs explicitly can reduce the attack surface. Network segmentation and endpoint detection and response (EDR) solutions should be used to monitor for suspicious behavior indicative of whitelist bypass attempts. Regular audits of whitelist policies and execution logs will help identify anomalies. Finally, educating users about the risks of executing unauthorized scripts and maintaining strong access controls will further reduce exploitation likelihood.