CVE-2021-43729 in MiNi Router 28K
Summary
by MITRE • 05/20/2022
Pix-Link MiNi Router 28K.MiniRouter.20190211 was discovered to contain a stored cross-site scripting (XSS) vulnerability due to an unsanitized Security Key parameter.
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Analysis
by VulDB Data Team • 05/27/2022
The Pix-Link MiNi Router 28K.MiniRouter.20190211 represents a network device that falls under the category of embedded systems commonly used in residential and small office environments. This particular model contains a critical security flaw that stems from improper input validation within its web-based administration interface. The vulnerability manifests through a stored cross-site scripting flaw that occurs when the Security Key parameter is processed without adequate sanitization measures. This issue specifically affects the device's handling of user-supplied data within its configuration management functions, creating an attack vector that can be exploited by malicious actors to inject malicious scripts into the router's web interface.
The technical implementation of this vulnerability places it squarely within CWE-79 Cross-site Scripting category, which encompasses weaknesses that allow attackers to inject client-side scripts into web applications viewed by other users. The flaw operates through a stored XSS mechanism rather than a reflected or DOM-based variant, meaning that the malicious script is permanently stored on the server and executed whenever a victim accesses the affected page. The Security Key parameter serves as the entry point for this vulnerability, as it is directly incorporated into the web interface without proper encoding or validation. This allows an attacker to craft a malicious payload that gets stored in the router's configuration and subsequently executed in the context of other users' browsers who access the administrative interface.
The operational impact of this vulnerability extends beyond simple script execution, as it can enable attackers to perform a wide range of malicious activities within the network environment. An attacker who successfully exploits this vulnerability could potentially steal session cookies, redirect users to malicious sites, modify router configuration settings, or even escalate privileges within the device's administration interface. The stored nature of this XSS vulnerability means that the attack persists even after the initial injection, creating a long-term threat that can affect multiple users over time. Given that this is a network infrastructure device, the potential for network-wide compromise increases significantly, as the attacker could gain insights into network topology, user activities, or even establish persistent access points within the network.
Mitigation strategies for this vulnerability should focus on both immediate remediation and long-term security improvements. The primary fix involves implementing proper input sanitization and output encoding for all user-supplied parameters, particularly those used in administrative interfaces. Organizations should ensure that all parameters, especially those related to security configurations, are properly validated and escaped before being stored or displayed in web interfaces. This aligns with the ATT&CK technique T1059.007 Command and Scripting Interpreter: JavaScript, which emphasizes the importance of preventing script injection attacks in web applications. Additionally, network segmentation and monitoring should be implemented to detect unusual activity patterns that might indicate exploitation attempts. Regular security assessments and firmware updates are essential to maintain device security, as this vulnerability represents a common class of flaws that can be addressed through proper software development practices and security testing protocols.