CVE-2021-38534 in D3600
Summary
by MITRE • 08/11/2021
Certain NETGEAR devices are affected by stored XSS. This affects D3600 before 1.0.0.76, D6000 before 1.0.0.76, D6100 before 1.0.0.60, D6200 before 1.1.00.36, D6220 before 1.0.0.52, D6400 before 1.0.0.86, D7000 before 1.0.1.70, D7000v2 before 1.0.0.53, D8500 before 1.0.3.44, DC112A before 1.0.0.42, DGN2200v4 before 1.0.0.110, DGND2200Bv4 before 1.0.0.109, DM200 before 1.0.0.61, JR6150 before 1.0.1.18, PR2000 before 1.0.0.28, R6020 before 1.0.0.42, R6050 before 1.0.1.18, R6080 before 1.0.0.42, R6220 before 1.1.0.80, R6230 before 1.1.0.80, R6250 before 1.0.4.34, R6260 before 1.1.0.64, R6300v2 before 1.0.4.34, R6400 before 1.0.1.46, R6400v2 before 1.0.2.62, R6700 before 1.0.2.6, R6700v2 before 1.2.0.36, R6700v3 before 1.0.2.62, R6800 before 1.2.0.36, R6900 before 1.0.2.4, R6900P before 1.3.1.64, R6900v2 before 1.2.0.36, R7000 before 1.0.9.60, R7000P before 1.3.1.64, R7100LG before 1.0.0.50, R7300DST before 1.0.0.70, R7450 before 1.2.0.36, R7900 before 1.0.3.8, R7900P before 1.4.1.50, R8000 before 1.0.4.28, R8000P before 1.4.1.50, R8300 before 1.0.2.130, R8500 before 1.0.2.130, WNDR3400v3 before 1.0.1.24, WNR2020 before 1.1.0.62, WNR3500Lv2 before 1.2.0.62, XR450 before 2.3.2.40, and XR500 before 2.3.2.40.
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Analysis
by VulDB Data Team • 08/16/2021
The vulnerability identified as CVE-2021-38534 represents a stored cross-site scripting flaw affecting numerous NETGEAR networking devices across multiple product lines including routers, modems, and wireless access points. This vulnerability falls under the Common Weakness Enumeration category CWE-79 which specifically addresses Cross-Site Scripting flaws, making it a critical security concern for network infrastructure devices. The affected devices span various firmware versions, with specific thresholds indicating when the vulnerability was introduced, suggesting that these devices were likely deployed without proper input validation mechanisms in their web interfaces. The stored nature of this XSS vulnerability means that malicious input injected into the device's web management interface is permanently stored and executed whenever a victim accesses the affected page, rather than requiring a user to click on a malicious link. This characteristic significantly amplifies the attack surface as any user with access to the device's web interface could potentially be targeted.
The technical exploitation of this vulnerability occurs through the web-based management interface of affected NETGEAR devices, where user input is not properly sanitized before being stored and subsequently rendered back to users. Attackers can inject malicious JavaScript code through form fields or configuration parameters that are then stored on the device and executed in the context of other users' browsers who visit the management interface. This allows attackers to perform actions such as stealing session cookies, modifying device configurations, redirecting users to malicious sites, or even executing arbitrary commands on the device. The impact extends beyond simple data theft as the attacker could potentially gain persistent access to the device, modify network settings, or establish backdoors within the network infrastructure. The vulnerability affects a broad range of networking equipment including popular models like the R6700, R6900, and R7900 series routers, indicating a systemic issue in the web interface implementation across NETGEAR's product portfolio.
The operational impact of this vulnerability is severe for organizations relying on NETGEAR devices for their network infrastructure, as it provides attackers with a potential entry point into corporate networks through compromised management interfaces. The stored XSS allows for persistent attacks that can remain undetected for extended periods, as the malicious code executes automatically whenever legitimate users access the device's web interface. This creates a significant risk for network administrators who may unknowingly be targeted by attackers, potentially leading to unauthorized access to sensitive network configurations, data exfiltration, or disruption of network services. The vulnerability's widespread presence across multiple device models and firmware versions suggests that organizations may have numerous affected devices without realizing it, creating a substantial attack surface that could be exploited by threat actors. Security researchers have noted that this vulnerability could be leveraged in combination with other attack vectors to escalate privileges or move laterally within networks, making it particularly dangerous in enterprise environments where network segmentation may not be properly implemented.
Mitigation strategies for CVE-2021-38534 should focus on immediate firmware updates from NETGEAR, as the vendor has released patches addressing this specific vulnerability. Organizations should conduct comprehensive inventory assessments to identify all affected devices across their network infrastructure, particularly focusing on those with web management interfaces accessible from external networks. Network segmentation should be implemented to limit access to device management interfaces to authorized personnel only, and multi-factor authentication should be enabled where available. Additionally, organizations should monitor network traffic for suspicious activity related to these devices and implement web application firewalls to detect and prevent malicious payloads from being executed. The vulnerability demonstrates the importance of proper input validation and output encoding in web applications, aligning with ATT&CK technique T1190 which covers Web Shell deployment and T1071.3 which addresses application layer protocols. Security teams should also consider implementing network monitoring solutions that can detect anomalous behavior patterns consistent with XSS exploitation attempts, and establish incident response procedures specifically addressing compromised network device management interfaces to ensure rapid containment and remediation of affected systems.