CVE-2018-20326 in PLC Wireless Router
Summary
by MITRE
ChinaMobile PLC Wireless Router GPN2.4P21-C-CN devices with firmware W2001EN-00 have XSS via the cgi-bin/webproc?getpage=html/index.html var:subpage parameter.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 07/10/2024
The vulnerability CVE-2018-20326 affects ChinaMobile PLC Wireless Router GPN2.4P21-C-CN devices running firmware version W2001EN-00, representing a cross-site scripting flaw that enables remote code execution through improper input validation. This vulnerability resides in the web interface processing mechanism where the cgi-bin/webproc script fails to properly sanitize user-supplied parameters, specifically the subpage parameter within the getpage=html/index.html request chain. The affected device exposes a web management interface that processes user input without adequate sanitization, creating an avenue for malicious actors to inject malicious scripts into the router's web interface.
The technical exploitation of this vulnerability follows a classic XSS attack pattern where an attacker crafts a malicious URL containing script code within the subpage parameter. When a victim navigates to this crafted URL while authenticated to the router's web interface, the malicious script executes within the context of the router's web application, potentially allowing attackers to steal session cookies, modify router settings, or redirect users to malicious sites. The vulnerability stems from the device's failure to implement proper input validation and output encoding mechanisms, which are fundamental security controls recommended by the Open Web Application Security Project and aligned with CWE-79 Cross-site Scripting.
The operational impact of this vulnerability extends beyond simple script injection, as it provides attackers with persistent access to the router's administrative interface. Once exploited, attackers can maintain long-term control over the device, potentially using it as a pivot point for further network reconnaissance and attacks. The vulnerability affects the device's authentication and authorization mechanisms, allowing unauthorized users to gain administrative privileges. This represents a critical security flaw that violates the principle of least privilege and can lead to complete network compromise, as routers often serve as central points of network access and control. The attack vector is particularly concerning as it requires no local access or authentication, making it exploitable over the network.
Mitigation strategies for this vulnerability include immediate firmware updates from ChinaMobile PLC, which should address the input validation issues by implementing proper parameter sanitization and output encoding. Organizations should also implement network segmentation to limit access to router management interfaces, restrict administrative access through firewalls, and deploy web application firewalls to detect and block malicious script injection attempts. The vulnerability aligns with ATT&CK technique T1071.004 Application Layer Protocol: Web Protocols, where attackers exploit web application vulnerabilities to gain unauthorized access. Additionally, this flaw demonstrates the importance of input validation controls as outlined in the OWASP Top Ten and the CWE hierarchy for XSS vulnerabilities, emphasizing the need for comprehensive security testing of web interfaces in network infrastructure devices. Network administrators should also implement regular security assessments and vulnerability scanning to identify similar issues in other network equipment.