CVE-2019-20672 in RBR50
Summary
by MITRE
Certain NETGEAR devices are affected by stored XSS. This affects RBR50 before 2.3.5.30, RBS50 before 2.3.5.30, and RBK50 before 2.3.5.30.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 05/26/2024
The vulnerability CVE-2019-20672 represents a stored cross-site scripting flaw affecting several NETGEAR router models including RBR50 RBS50 and RBK50 series. This security weakness allows attackers to inject malicious scripts into the device's web interface that persist across user sessions and system reboots. The affected firmware versions prior to 2.3.5.30 demonstrate a critical oversight in input validation and output sanitization mechanisms within the device's management interface. The vulnerability stems from insufficient filtering of user-supplied data when processing configuration parameters and administrative inputs through the web-based management portal.
The technical implementation of this stored XSS vulnerability occurs when administrators or legitimate users interact with the affected NETGEAR devices through their web interfaces. Attackers can exploit this flaw by crafting malicious payloads that get stored in the device's configuration or logging mechanisms. When other users access the vulnerable interface or when the device displays stored data, the malicious scripts execute in the context of the victim's browser session. This creates a persistent threat vector that can compromise user sessions and potentially escalate privileges within the local network environment. The vulnerability aligns with CWE-79 which specifically addresses cross-site scripting flaws, and represents a classic case of stored XSS where malicious input is permanently saved and later executed without proper sanitization.
The operational impact of CVE-2019-20672 extends beyond simple script execution as it provides attackers with significant opportunities for network compromise. Once an attacker successfully injects malicious code, they can potentially steal administrative credentials, redirect users to malicious sites, or manipulate device configurations to create backdoors. The persistent nature of stored XSS means that even after the initial attack vector is closed, the malicious code continues to execute whenever affected pages are loaded. This vulnerability particularly affects enterprise and home network environments where these routers serve as primary gateways, potentially allowing attackers to gain unauthorized access to internal network resources. The attack surface is further expanded through ATT&CK framework's T1071.004 technique for application layer protocol usage and T1566 for credential access through social engineering.
Mitigation strategies for this vulnerability require immediate firmware updates to versions 2.3.5.30 or later where NETGEAR has addressed the input validation gaps. Network administrators should also implement additional security controls including web application firewalls that can detect and block XSS payloads, regular monitoring of device management interfaces for suspicious activity, and network segmentation to limit the potential impact of successful exploitation. The vulnerability highlights the importance of input validation and output encoding practices as recommended by OWASP top ten security guidelines. Organizations should conduct comprehensive vulnerability assessments of their network infrastructure to identify other potentially affected devices and ensure proper patch management procedures are in place to address similar issues across all network equipment. Regular security audits of web-based management interfaces should include testing for XSS vulnerabilities and other injection flaws to maintain robust network security postures.