CVE-2019-20720 in D3600
Summary
by MITRE
Certain NETGEAR devices are affected by stored XSS. This affects D3600 before 1.0.0.76, D6000 before 1.0.0.76, D7800 before 1.0.1.47, R7500v2 before 1.0.3.38, R7800 before 1.0.2.52, R8900 before 1.0.4.12, R9000 before 1.0.4.12, WN2000RPTv3 before 1.0.1.32, WN3000RPv3 before 1.0.2.70, and WN3100RPv2 before 1.0.0.66.
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Analysis
by VulDB Data Team • 05/31/2024
The vulnerability identified as CVE-2019-20720 represents a critical stored cross-site scripting flaw affecting multiple NETGEAR networking devices across various product lines. This security weakness resides in the web-based management interfaces of affected routers and access points, creating a persistent threat vector that can be exploited by attackers who gain access to the device's administrative functions. The vulnerability impacts a significant number of consumer and small office networking devices, including the D3600, D6000, D7800, R7500v2, R7800, R8900, R9000, WN2000RPTv3, WN3000RPv3, and WN3100RPv2 models. These devices are widely deployed in residential and small business environments, making the potential impact of this vulnerability substantial. The affected firmware versions all precede specific security updates released by NETGEAR, indicating that the flaw was present in the device software for an extended period, potentially allowing attackers to exploit it without detection.
The technical implementation of this stored XSS vulnerability occurs within the web interface handling of user input fields, particularly those related to device configuration parameters. When administrators or authenticated users enter malicious content into specific input fields, the application fails to properly sanitize or escape the data before storing it in the device's persistent memory. This stored data is then later retrieved and displayed in the web interface without adequate output encoding, creating an environment where malicious scripts can execute in the context of the victim's browser session. The flaw specifically affects how the device processes and renders user-supplied data, allowing attackers to inject malicious JavaScript code that persists across multiple sessions and browser refreshes. This stored nature of the vulnerability means that even after the initial injection, the malicious code continues to execute whenever the affected web interface is accessed, creating a persistent threat that can be exploited by anyone with access to the device's management interface.
The operational impact of this vulnerability extends beyond simple data theft or service disruption, as it creates a potential pathway for more sophisticated attacks within the network environment. An attacker who can successfully exploit this vulnerability gains the ability to execute arbitrary code within the browser context of authenticated users, potentially leading to complete device compromise, unauthorized access to network resources, or redirection to malicious sites. The vulnerability aligns with CWE-79, which specifically addresses cross-site scripting flaws, and represents a significant risk to network security since these devices often serve as gateways to home and small office networks. From an ATT&CK framework perspective, this vulnerability enables techniques such as credential theft, privilege escalation, and initial access through web application exploitation, potentially allowing attackers to establish persistent access points within the network infrastructure. The impact is particularly concerning given that many of these devices are configured with default administrative credentials that may not be changed by end users, providing attackers with minimal barriers to entry.
Organizations and users should immediately implement mitigations including firmware updates from NETGEAR that address this specific vulnerability, as the company released patches for all affected models. Network segmentation and access control measures should be implemented to limit access to device management interfaces to authorized personnel only, while monitoring for unusual network traffic patterns that might indicate exploitation attempts. Regular security audits of network infrastructure should include verification of device firmware versions and proper configuration practices. The vulnerability also highlights the importance of maintaining up-to-date security patches and implementing network monitoring solutions that can detect anomalous behavior in network devices. Users should be educated about the risks of accessing device management interfaces from untrusted networks or devices, as the vulnerability could be exploited through social engineering or other means to gain initial access to the device's administrative functions. Additionally, implementing network access controls such as firewalls that restrict access to device management ports from external networks can significantly reduce the attack surface for this and similar vulnerabilities.