CVE-2018-7933 in HiRouter-CD20
Summary
by MITRE
Huawei home gateway products HiRouter-CD20 and WS5200 with the versions before HiRouter-CD20-10 1.9.6 and the versions before WS5200-10 1.9.6 have a path traversal vulnerability. Due to the lack of validation while these home gateway products install APK plugins, an attacker tricks a user into installing a malicious APK plugin, and plugin can overwrite arbitrary file of devices. Successful exploit may result in arbitrary code execution or privilege escalation.
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Analysis
by VulDB Data Team • 03/11/2023
The vulnerability identified as CVE-2018-7933 affects Huawei home gateway products including the HiRouter-CD20 and WS5200 models. This security flaw resides in the plugin installation mechanism of these network devices, specifically within versions prior to HiRouter-CD20-10 1.9.6 and WS5200-10 1.9.6. The core issue stems from insufficient input validation during the APK plugin installation process, creating a path traversal vulnerability that allows malicious actors to manipulate the device's file system. This weakness represents a critical security gap that directly violates the principle of least privilege and proper input sanitization, as outlined in CWE-22 which categorizes path traversal vulnerabilities as a fundamental flaw in software security design.
The technical exploitation of this vulnerability occurs through a sophisticated social engineering attack vector where an attacker deceives users into installing a malicious APK plugin. Once installed, the malicious plugin leverages the path traversal flaw to overwrite arbitrary files on the device's file system, potentially compromising the entire device's integrity. This vulnerability operates at the system level, allowing for privilege escalation and arbitrary code execution capabilities that could enable attackers to gain full control over the affected home gateway. The attack chain follows the typical pattern of initial user deception followed by privilege escalation, which aligns with ATT&CK technique T1059 for command and script injection, and T1068 for exploit for privilege escalation.
The operational impact of this vulnerability extends beyond simple device compromise, as home gateways serve as critical network infrastructure points that control internet access and network security for entire households or small businesses. Successful exploitation could result in complete network takeover, enabling attackers to monitor traffic, redirect connections, or establish persistent backdoors. The vulnerability affects devices that are typically located in unsecured environments, making them particularly attractive targets for attackers seeking persistent access to home networks. Network administrators and end users face significant risk as these devices often operate with default credentials and lack regular security updates, creating a persistent threat surface that could be exploited for broader network attacks.
Mitigation strategies for CVE-2018-7933 should focus on immediate firmware updates to versions 1.9.6 or later where the path traversal vulnerability has been patched. Organizations and individuals should implement strict plugin installation policies, avoiding installation of unsigned or untrusted APK plugins from unknown sources. Network segmentation and monitoring should be enhanced to detect unusual plugin installation activities or file system modifications. The vulnerability highlights the importance of secure software development practices, particularly in IoT and networking equipment where user interaction with device management interfaces is common. Regular security assessments of network infrastructure, including vulnerability scanning and penetration testing, should be conducted to identify similar flaws in other network devices. Additionally, implementing network access controls and firewall rules that restrict plugin installation capabilities can provide additional defense in depth measures against this type of attack vector.