CVE-2018-6686 in Drive Encryption
Summary
by MITRE
Authentication Bypass vulnerability in TPM autoboot in McAfee Drive Encryption (MDE) 7.1.0 and above allows physically proximate attackers to bypass local security protection via specific set of circumstances.
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Analysis
by VulDB Data Team • 04/27/2023
The vulnerability identified as CVE-2018-6686 represents a critical authentication bypass flaw within the Trusted Platform Module (TPM) autoboot functionality of McAfee Drive Encryption version 7.1.0 and later. This weakness specifically targets the local security mechanisms that rely on TPM-based authentication to protect encrypted volumes, creating a significant risk for systems where physical proximity can be achieved by malicious actors. The vulnerability operates through a combination of specific environmental conditions and system configurations that allow unauthorized access to encrypted data without proper authentication credentials. The attack vector requires physical proximity to the target system, making it particularly concerning for environments where unauthorized individuals might gain access to devices in controlled or semi-controlled spaces.
The technical implementation of this vulnerability stems from improper handling of TPM state transitions during the autoboot process within McAfee Drive Encryption. When the system attempts to authenticate using TPM credentials during boot, certain conditions can cause the authentication mechanism to fail or be bypassed entirely. This occurs because the software fails to properly validate the TPM state or does not adequately enforce the required authentication checks that should occur before granting access to encrypted volumes. The flaw exists in the way the system processes TPM measurements and comparisons during the boot sequence, allowing attackers to manipulate or bypass the expected security checks that should prevent unauthorized access to encrypted data. This type of vulnerability aligns with CWE-287, which addresses improper authentication issues in software systems, and specifically relates to improper credential handling during system boot processes.
The operational impact of CVE-2018-6686 extends beyond simple data exposure, as it fundamentally undermines the core security model of drive encryption systems. Attackers exploiting this vulnerability can gain access to encrypted volumes without proper authentication, potentially compromising sensitive data stored on the affected systems. The physical proximity requirement means that this vulnerability is particularly dangerous in environments where devices are left unattended or where unauthorized individuals might gain access to workstations in shared or public spaces. Organizations using McAfee Drive Encryption may face significant security implications including potential data breaches, compliance violations, and loss of confidential information. The vulnerability affects systems where TPM-based authentication is enabled, which represents a substantial portion of enterprise encryption deployments that rely on hardware security modules for protecting sensitive data.
Mitigation strategies for this vulnerability require immediate attention from system administrators and security teams responsible for managing McAfee Drive Encryption implementations. The primary recommendation involves applying the official security patches provided by McAfee to address the specific TPM autoboot authentication bypass issue. Organizations should also implement additional security controls including disabling TPM-based autoboot functionality when not required, implementing strict physical security measures to prevent unauthorized access to systems, and monitoring for unusual boot patterns or authentication attempts. Security teams should consider implementing network-based monitoring solutions to detect potential exploitation attempts and establish incident response procedures specifically addressing this type of authentication bypass vulnerability. The mitigation approach should align with ATT&CK framework techniques related to privilege escalation and credential access, as this vulnerability essentially allows attackers to bypass credential validation mechanisms that should protect encrypted data. Organizations must also conduct comprehensive audits of their encryption implementations to identify other potential vulnerabilities in their security infrastructure and ensure that all systems are properly patched and configured according to security best practices.