CVE-2016-4850 in LINE
Summary
by MITRE
LINE for Windows before 4.8.3 allows man-in-the-middle attackers to execute arbitrary code.
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Analysis
by VulDB Data Team • 12/21/2020
The vulnerability identified as CVE-2016-4850 affects LINE for Windows client software versions prior to 4.8.3, representing a critical security flaw that enables man-in-the-middle attacks with arbitrary code execution capabilities. This vulnerability specifically targets the client-side implementation of the LINE messaging application on Windows operating systems, creating a significant risk for users who rely on the platform for communication and data exchange.
The technical flaw stems from inadequate certificate validation mechanisms within the LINE client's secure communication implementation. Attackers can exploit this weakness by intercepting network traffic between the client and LINE's servers, presenting forged SSL/TLS certificates that appear legitimate to the vulnerable client application. This allows malicious actors to establish fraudulent connections while maintaining the appearance of secure communication, effectively bypassing the intended security controls. The vulnerability operates at the transport layer security validation level, making it particularly dangerous as it undermines the fundamental trust model of encrypted communications.
The operational impact of this vulnerability extends beyond simple data interception, as it provides attackers with full arbitrary code execution capabilities on affected systems. This means that compromised users could have their devices infected with malware, sensitive information stolen, or their communication sessions hijacked for malicious purposes. The vulnerability affects all users running LINE for Windows versions before 4.8.3, creating a widespread risk across various user bases including individuals, businesses, and organizations that utilize the platform for communication. The implications are particularly severe given that LINE is widely used in both personal and professional contexts, making the potential attack surface extensive.
Security researchers have classified this vulnerability under CWE-295 which specifically addresses improper certificate validation in secure communications. The attack vector aligns with ATT&CK technique T1041 which covers data compression and encryption for exfiltration, while also mapping to T1566 which covers credential harvesting through social engineering and network attacks. Organizations should immediately implement patch management protocols to upgrade to LINE for Windows version 4.8.3 or later, which includes improved certificate validation mechanisms and enhanced security controls. Network administrators should also consider implementing additional monitoring for suspicious SSL/TLS handshake patterns and certificate anomalies. The vulnerability demonstrates the critical importance of maintaining up-to-date client software and proper certificate validation practices in preventing sophisticated man-in-the-middle attacks that can lead to full system compromise.