CVE-2018-4217 in macOS
Summary
by MITRE
In macOS High Sierra before 10.13.5, a privacy issue in the handling of Open Directory records was addressed with improved indexing.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 04/29/2020
The vulnerability described in CVE-2018-4217 represents a privacy flaw within macOS High Sierra versions prior to 10.13.5, specifically concerning the Open Directory service implementation. This issue stems from inadequate handling of directory records that could potentially expose sensitive user information through improper indexing mechanisms. The Open Directory service in macOS provides centralized user authentication and directory services that are fundamental to enterprise and organizational security infrastructures. When systems fail to properly index directory records, they may inadvertently leak information about user accounts, group memberships, or other directory attributes that should remain protected within controlled access environments. This vulnerability particularly affects systems where macOS acts as a directory server or where directory services are actively utilized for user management and authentication purposes.
The technical flaw manifests in the way macOS processes and indexes Open Directory records, creating potential information disclosure channels that could be exploited by malicious actors. This type of vulnerability aligns with CWE-200, which addresses "Information Exposure," and specifically relates to improper access control mechanisms within directory services. The indexing mechanism fails to properly sanitize or restrict access to directory attributes, potentially allowing unauthorized information retrieval through crafted queries or direct access attempts. Attackers could leverage this weakness to enumerate user accounts, discover group memberships, or extract other directory information that should remain confidential within properly secured environments. The vulnerability essentially creates a pathway for information leakage that violates fundamental security principles of least privilege and access control.
The operational impact of this vulnerability extends beyond simple information disclosure, potentially compromising the overall security posture of macOS systems within enterprise environments. Organizations relying on macOS for directory services may experience unauthorized access to sensitive user information, which could facilitate further attacks including credential harvesting, social engineering campaigns, or privilege escalation attempts. The vulnerability affects systems where Open Directory is actively used for user authentication and management, making it particularly concerning for organizations that depend on macOS for their directory infrastructure. This issue could enable attackers to gather intelligence about network users, identify potential targets for phishing attacks, or map out organizational structures that could aid in more sophisticated exploitation efforts. The implications are especially severe in environments where macOS servers serve as directory authorities for large user bases.
Mitigation strategies for CVE-2018-4217 primarily focus on updating to macOS High Sierra version 10.13.5 or later, which includes the necessary patches to address the improper indexing of Open Directory records. System administrators should prioritize patch management and ensure all macOS systems are updated to the latest security releases. Additional defensive measures include implementing proper network segmentation to limit access to directory services, monitoring directory access logs for unusual query patterns, and conducting regular security audits of directory service configurations. Organizations should also review their access controls and authentication mechanisms to ensure that directory service access is properly restricted to authorized personnel only. The remediation process should include verification that the indexing improvements have been properly implemented and that no information leakage pathways remain. This vulnerability demonstrates the importance of maintaining up-to-date security patches and proper configuration management in preventing information disclosure attacks that could compromise entire organizational infrastructures.