CVE-2020-24159 in NetEase Youdao Dictionary
Summary
by MITRE
NetEase Youdao Dictionary has a DLL hijacking vulnerability, which can be exploited by attackers to gain server permissions. This affects Guangzhou NetEase Youdao Dictionary 8.9.2.0.
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Analysis
by VulDB Data Team • 09/04/2020
The CVE-2020-24159 vulnerability represents a critical DLL hijacking flaw within the NetEase Youdao Dictionary application version 8.9.2.0, specifically targeting systems in Guangzhou. This vulnerability stems from improper dynamic link library loading mechanisms that allow malicious actors to inject arbitrary code into the legitimate application process. The flaw occurs when the application fails to properly specify the full path for dynamically loaded libraries, creating opportunities for attackers to place malicious DLL files in directories that are searched before the legitimate system directories. This vulnerability directly aligns with CWE-426, which categorizes insecure library loading practices as a significant security risk. The attack vector typically involves placing a specially crafted malicious DLL file in a location that gets prioritized during the library search process, allowing the attacker to execute code with the privileges of the running process.
The operational impact of this vulnerability extends beyond simple code execution, as it can enable attackers to escalate privileges and gain full control over the affected server systems. When exploited, the vulnerability allows adversaries to execute arbitrary commands on the target machine, potentially leading to complete system compromise and persistent access. The affected NetEase Youdao Dictionary version 8.9.2.0 represents a specific implementation that fails to properly validate or resolve library paths, creating a window for attackers to manipulate the application's execution flow. This vulnerability particularly affects server environments where the dictionary application might be running with elevated privileges, making the potential impact significantly more severe. The attack can be executed through various methods including social engineering to trick users into installing malicious software or by directly placing the malicious DLL in strategic locations within the system. This type of vulnerability is often categorized under the ATT&CK framework as T1059.001 for Command and Scripting Interpreter, where attackers leverage legitimate system tools to execute malicious code.
Mitigation strategies for CVE-2020-24159 should focus on implementing proper DLL loading practices and system hardening measures. Organizations should ensure that all applications implement secure library loading by using absolute paths for dynamic libraries or by configuring the application's DLL search order to prioritize system directories. The recommended approach involves applying the principle of least privilege by running applications with minimal required permissions and implementing strict file system access controls. System administrators should conduct thorough security audits to identify and remove any unnecessary applications or components that might be vulnerable to similar attacks. Additionally, deploying application whitelisting solutions and monitoring for unusual DLL loading activities can help detect potential exploitation attempts. The vulnerability highlights the importance of secure coding practices and proper input validation, as outlined in the OWASP Top Ten security principles. Regular updates and patches should be applied immediately upon availability, and organizations should implement network segmentation to limit the potential impact of successful exploitation. Security monitoring should include detection of suspicious file placement activities and unauthorized DLL loading events to provide early warning of potential attacks.