CVE-2021-38528 in D8500
Summary
by MITRE • 08/11/2021
Certain NETGEAR devices are affected by command injection by an unauthenticated attacker. This affects D8500 before 1.0.3.58, R6900P before 1.3.2.132, R7000P before 1.3.2.132, R7100LG before 1.0.0.64, WNDR3400v3 before 1.0.1.38, and XR300 before 1.0.3.56.
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Analysis
by VulDB Data Team • 08/16/2021
This vulnerability represents a critical command injection flaw in NETGEAR networking equipment that allows unauthenticated attackers to execute arbitrary commands on affected devices. The vulnerability stems from improper input validation within the web interface of these routers and wireless access points, creating an avenue for remote code execution without requiring authentication credentials. The affected models span multiple device families including the D8500, R6900P, R7000P, R7100LG, WNDR3400v3, and XR300 series, all of which share a common software implementation that fails to properly sanitize user-supplied input before processing. The vulnerability specifically impacts devices running firmware versions prior to the mentioned patches, indicating a software-level flaw rather than a hardware design issue. This type of vulnerability falls under CWE-77 and CWE-94 categories, representing command injection and code injection weaknesses respectively, where attacker-controlled data is interpreted as executable commands by the system. The security implications are severe as an unauthenticated attacker can leverage this vulnerability to gain complete control over the affected network devices, potentially leading to man-in-the-middle attacks, data exfiltration, or network compromise. The attack surface is particularly concerning given that these are consumer and small office networking devices that are often deployed in environments where network security is not properly configured or monitored. The vulnerability allows for arbitrary command execution, which means attackers can perform actions such as modifying device configuration, installing malicious software, creating backdoors, or redirecting network traffic. From an operational perspective, this vulnerability presents a significant risk to network infrastructure as these devices typically serve as the primary gateway between internal networks and external internet access. The impact extends beyond individual device compromise to potentially affect entire network segments that rely on these devices for connectivity and security policies. The attack vector is straightforward as it requires no authentication and can be exploited through web interface interactions, making it particularly dangerous for devices deployed in public or unsecured environments. Organizations using these affected devices should immediately implement mitigations including firmware updates, network segmentation, and monitoring for suspicious network activity. The vulnerability also aligns with ATT&CK technique T1059.001 for command and script injection, representing a pathway for attackers to establish persistence and escalate privileges within compromised networks. The widespread deployment of these affected devices across both residential and small business environments means that this vulnerability affects a significant number of network endpoints that may not receive regular security updates or monitoring. This vulnerability demonstrates the critical importance of secure software development practices and the need for regular firmware updates to address security flaws that can be exploited remotely. The lack of authentication requirements for exploitation makes this particularly dangerous as it requires no prior access to the network or device credentials. Network administrators should consider implementing network access controls and intrusion detection systems to monitor for exploitation attempts, while also planning for immediate firmware upgrades across all affected device models to remediate the vulnerability. The vulnerability serves as a reminder of the importance of network security hygiene and the risks associated with legacy network equipment that may not receive regular security updates or patches from vendors.