CVE-2016-4831 in LINE
Summary
by MITRE
Untrusted search path vulnerability in LINE and LINE Installer 4.7.0 and earlier on Windows allows local users to gain privileges via a Trojan horse DLL in an unspecified directory.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 02/22/2019
The vulnerability identified as CVE-2016-4831 represents a critical untrusted search path issue affecting LINE and LINE Installer versions 4.7.0 and earlier on Windows operating systems. This flaw resides in the application's dynamic link library loading mechanism, where the software fails to properly validate the source and integrity of dynamically loaded modules. The vulnerability stems from the application's insecure handling of the Windows DLL search order, which prioritizes loading libraries from the current working directory before checking system directories, creating an exploitable condition for privilege escalation attacks.
The technical implementation of this vulnerability allows local attackers to place malicious DLL files in directories that the LINE application will prioritize during execution. When the vulnerable application launches, it automatically loads these malicious libraries without proper verification, enabling attackers to execute arbitrary code with the privileges of the target user. This behavior aligns with CWE-426, which describes the insecure use of a command or API that allows an attacker to inject code or commands into the application's execution path. The vulnerability specifically exploits the Windows search order precedence where the current working directory is checked before system directories, a well-documented weakness in legacy application design patterns.
The operational impact of this vulnerability extends beyond simple privilege escalation to encompass potential system compromise and data exfiltration. An attacker with local access can leverage this vulnerability to elevate their privileges and gain unauthorized access to sensitive information or system resources. The attack vector is particularly concerning because it requires minimal user interaction beyond the initial installation or execution of the vulnerable software, making it a persistent threat in environments where users have local access rights. This vulnerability directly maps to ATT&CK technique T1068, which covers privilege escalation through the exploitation of vulnerabilities in software applications, and T1059, which involves the use of command and scripting interpreters.
Mitigation strategies for CVE-2016-4831 must address both the immediate software vulnerability and broader system security posture. The primary remediation involves updating to LINE and LINE Installer versions that have been patched to properly implement secure DLL loading practices, ensuring that applications load libraries from trusted system directories only. Organizations should implement application whitelisting policies to prevent unauthorized DLL execution, and deploy security controls such as Windows AppLocker or similar application control mechanisms to restrict which binaries can execute on the system. Additionally, system administrators should conduct regular security audits to identify and remediate similar insecure search path vulnerabilities across the enterprise, particularly in legacy applications that may not have received recent security updates. The vulnerability demonstrates the critical importance of secure coding practices and proper DLL loading mechanisms, reinforcing industry standards that emphasize the need for robust input validation and secure library loading procedures to prevent such exploitation vectors.