CVE-2021-38535 in D6200
Summary
by MITRE • 08/11/2021
Certain NETGEAR devices are affected by stored XSS. This affects D6200 before 1.1.00.40, D7000 before 1.0.1.78, R6020 before 1.0.0.48, R6080 before 1.0.0.48, R6120 before 1.0.0.76, R6260 before 1.1.0.78, R6700v2 before 1.2.0.76, R6800 before 1.2.0.76, R6900v2 before 1.2.0.76, R6850 before 1.1.0.78, R7200 before 1.2.0.76, R7350 before 1.2.0.76, R7400 before 1.2.0.76, R7450 before 1.2.0.76, AC2100 before 1.2.0.76, AC2400 before 1.2.0.76, AC2600 before 1.2.0.76, RAX35 before 1.0.3.62, and RAX40 before 1.0.3.62.
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Analysis
by VulDB Data Team • 08/16/2021
This vulnerability represents a critical stored cross-site scripting flaw affecting multiple NETGEAR router models across various product lines including wireless routers, access points, and networking equipment. The vulnerability stems from insufficient input validation and output encoding within the web-based management interfaces of these devices, allowing attackers to inject malicious scripts that persist in the device's memory and execute when other users access the administration panel. The affected models span several generations of NETGEAR's consumer and enterprise networking products, with specific version thresholds indicating that devices running firmware versions prior to the listed patches remain vulnerable.
The technical exploitation of this stored XSS vulnerability occurs when an attacker crafts malicious input through web forms or parameters within the router's administrative interface and submits it to the device. These inputs are then stored within the device's configuration or session management systems without proper sanitization. When legitimate users or administrators subsequently access the affected web interface, the malicious scripts execute in their browsers, potentially leading to session hijacking, credential theft, or unauthorized administrative access. This type of vulnerability falls under CWE-79 which specifically addresses cross-site scripting flaws in software applications.
The operational impact of this vulnerability extends beyond simple script execution as it provides attackers with persistent access to network administration functions. An attacker who successfully exploits this vulnerability can potentially gain complete control over the affected router, enabling them to modify network configurations, redirect traffic, monitor network activity, or establish persistent backdoors within the network infrastructure. The long-term persistence of stored XSS makes this particularly dangerous as the malicious payload remains active even after device reboots or normal operation cycles, creating a continuous threat vector for network compromise.
Network security professionals should prioritize immediate remediation of affected devices through firmware updates provided by NETGEAR. The vulnerability affects a broad range of consumer and small business networking equipment, making it a significant concern for organizations that may have these devices deployed in their networks. Organizations should conduct comprehensive inventories to identify all affected devices and implement network monitoring to detect potential exploitation attempts. The ATT&CK framework categorizes this vulnerability under T1071.004 for application layer protocol usage and T1566 for credential access through social engineering, emphasizing the multi-faceted attack surface this vulnerability presents. Additionally, network segmentation and restricted administrative access controls should be implemented as defensive measures while firmware updates are deployed. The vulnerability demonstrates the importance of proper input validation and output encoding practices in web applications, particularly those managing critical network infrastructure components.