CVE-2021-38515 in R6400v2
Summary
by MITRE • 08/11/2021
Certain NETGEAR devices are affected by denial of service. This affects R6400v2 before 1.0.4.98, R6700v3 before 1.0.4.98, R7900 before 1.0.3.18, and R8000 before 1.0.4.46.
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Analysis
by VulDB Data Team • 08/16/2021
This vulnerability affects multiple NETGEAR router models including R6400v2, R6700v3, R7900, and R8000, representing a denial of service condition that can disrupt network connectivity for affected devices. The issue stems from improper handling of certain network packets or configuration parameters within the device firmware, specifically impacting versions prior to the mentioned security patches. The vulnerability allows an attacker to potentially cause the affected routers to become unresponsive or restart unexpectedly, effectively denying network services to legitimate users.
The technical flaw manifests as a failure in input validation or resource management within the router's network processing components. When specific malformed packets or configuration requests are sent to the affected devices, the firmware fails to properly handle these inputs, leading to system instability or complete service disruption. This type of vulnerability typically falls under CWE-20, which represents "Improper Input Validation," and can be classified as a resource exhaustion or control flow manipulation issue within the network stack processing.
The operational impact of this vulnerability extends beyond simple service disruption as it can compromise network availability for organizations and consumers relying on these devices. Network administrators may experience unexpected downtime, while end users could face complete loss of internet connectivity. The vulnerability affects enterprise and home networks alike, potentially impacting critical business operations or personal connectivity. In larger deployments, multiple affected devices could cause cascading failures across network infrastructure.
Mitigation strategies should focus on immediate firmware updates to the latest versions that address the specific denial of service condition. Network administrators should prioritize patching all affected devices in their inventory, particularly those serving critical network functions. Additional defensive measures include implementing network segmentation to limit exposure, deploying intrusion detection systems to monitor for suspicious traffic patterns, and establishing network monitoring protocols to quickly identify service disruptions. The vulnerability demonstrates the importance of maintaining up-to-date firmware across network infrastructure devices and aligns with ATT&CK technique T1499.004 for Network Denial of Service attacks. Organizations should also consider implementing device authentication mechanisms and network access controls to limit potential attack vectors. Regular vulnerability assessments and security audits of network infrastructure can help identify other potential weaknesses that may compound the risk from such denial of service conditions.