CVE-2020-24161 in NetEase Mail Master
Summary
by MITRE
Guangzhou NetEase Mail Master 4.14.1.1004 on Windows has a DLL hijacking vulnerability. Attackers can use this vulnerability to execute malicious code.
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Analysis
by VulDB Data Team • 09/04/2020
The vulnerability identified as CVE-2020-24161 affects Guangzhou NetEase Mail Master version 4.14.1.1004 running on Windows operating systems, representing a critical DLL hijacking flaw that exposes the application to unauthorized code execution. This vulnerability stems from improper dynamic link library loading mechanisms within the mail client software, creating an exploitable pathway for malicious actors to inject and execute arbitrary code on targeted systems.
The technical implementation of this vulnerability involves the application's failure to properly validate and resolve dynamic link library dependencies during runtime execution. When the mail master application attempts to load required DLL files, it follows a predictable search order that can be manipulated by attackers to load malicious libraries from unauthorized locations. This behavior aligns with CWE-426, which describes the insecure loading of dynamic libraries, and represents a classic example of how improper DLL search order handling can be exploited to achieve privilege escalation and code execution. The vulnerability specifically exploits the Windows DLL loading mechanism where applications first search in the current working directory before examining system directories, allowing attackers to place malicious DLLs in strategic locations.
The operational impact of this vulnerability extends beyond simple code execution, as it provides attackers with a foothold for more sophisticated attacks within the compromised environment. Once successful, the malicious code execution can lead to complete system compromise, data exfiltration, and potential lateral movement within networked environments. Attackers can leverage this vulnerability to establish persistent access, deploy additional malware payloads, or conduct reconnaissance activities without detection. The attack surface is particularly concerning given that mail client applications often run with elevated privileges and have access to sensitive user data, making this vulnerability a prime target for threat actors seeking to gain unauthorized access to corporate networks or personal systems.
Mitigation strategies for CVE-2020-24161 should focus on both immediate remediation and long-term security hardening measures. The primary recommendation involves updating to the latest version of Guangzhou NetEase Mail Master where the vulnerability has been patched, as this addresses the root cause of the improper DLL loading behavior. Organizations should also implement application whitelisting policies to restrict which DLLs can be loaded by the application, utilize Windows Defender Application Control or similar technologies to enforce code integrity, and monitor for suspicious DLL loading activities through endpoint detection and response systems. Additionally, security teams should consider implementing the principle of least privilege for mail client applications and regularly audit application dependencies to ensure no unauthorized DLLs are present in application directories. This vulnerability demonstrates the importance of following secure coding practices and adheres to ATT&CK technique T1574.001 for DLL side-loading, making it a critical consideration for organizations implementing comprehensive security frameworks.