CVE-2017-6988 in macOS
Summary
by MITRE
An issue was discovered in certain Apple products. macOS before 10.12.5 is affected. The issue involves the "802.1X" component. It allows remote attackers to discover the network credentials of arbitrary users by operating a crafted network that requires 802.1X authentication, because EAP-TLS certificate validation mishandles certificate changes.
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Analysis
by VulDB Data Team • 09/02/2024
The vulnerability identified as CVE-2017-6988 represents a critical security flaw in Apple's macOS operating system affecting versions prior to 10.12.5. This weakness specifically targets the 802.1X authentication component which is fundamental to enterprise network security protocols. The issue stems from improper handling of EAP-TLS certificate validation during network authentication processes, creating a significant attack vector that undermines the integrity of wireless network communications. The vulnerability operates at the network layer where authentication credentials are exchanged, making it particularly dangerous in corporate environments where 802.1X is commonly deployed for securing wireless access points.
The technical flaw manifests when an attacker creates a malicious network infrastructure that requires 802.1X authentication with EAP-TLS method. Under normal circumstances, EAP-TLS should validate certificates through strict verification processes that ensure certificate changes are properly authenticated and validated. However, this vulnerability allows attackers to exploit a flaw in the certificate validation mechanism where certificate changes are not adequately verified. The attack exploits the trust relationship between the client and authentication server by manipulating the certificate exchange process during authentication. This misconfiguration enables attackers to intercept and potentially obtain network credentials from users who connect to the malicious network, effectively bypassing the intended security controls.
The operational impact of CVE-2017-6988 extends beyond simple credential theft, as it represents a sophisticated man-in-the-middle attack capability that can compromise entire network access controls. Attackers can leverage this vulnerability to perform passive credential harvesting without requiring user interaction or explicit authentication attempts. The flaw particularly affects environments where wireless networks utilize 802.1X authentication, which is standard in enterprise and educational institutions. Organizations running affected macOS versions face significant risk of unauthorized access to their networks, potentially leading to data breaches, privilege escalation, and lateral movement within network infrastructure. This vulnerability aligns with attack patterns described in the mitre ATT&CK framework under credential access and defense evasion techniques, specifically targeting network protocols and authentication mechanisms.
Security professionals should recognize this vulnerability as a variant of certificate validation flaws commonly classified under CWE-295 which addresses improper certificate validation. The attack scenario demonstrates how weak certificate handling can create persistent security gaps even when strong cryptographic protocols are in place. Organizations should implement immediate mitigations including updating to macOS 10.12.5 or later, deploying network monitoring solutions to detect suspicious authentication patterns, and reviewing 802.1X configuration settings. Additionally, network administrators should consider implementing certificate pinning mechanisms and enhanced network access control policies to reduce the attack surface. The vulnerability highlights the importance of proper cryptographic implementation and demonstrates how subtle flaws in certificate validation can have severe consequences for network security posture.