CVE-2018-21166 in R6100
Summary
by MITRE
Certain NETGEAR devices are affected by denial of service. This affects R6100 before 1.0.1.22, R7500 before 1.0.0.122, R7800 before 1.0.2.42, R8900 before 1.0.3.10, R9000 before 1.0.3.10, WNDR3700v4 before 1.0.2.96, WNDR4300 before 1.0.2.98, WNDR4300v2 before 1.0.0.54, WNDR4500v3 before 1.0.0.54, and WNR2000v5 before 1.0.0.64.
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Analysis
by VulDB Data Team • 06/02/2024
This vulnerability affects multiple NETGEAR wireless routers and access points across various product lines including the R6100, R7500, R7800, R8900, R9000, WNDR3700v4, WNDR4300, WNDR4300v2, WNDR4500v3, and WNR2000v5 models. The flaw manifests as a denial of service condition that can disrupt network connectivity and render affected devices inoperable. The vulnerability specifically impacts firmware versions prior to the mentioned patches, indicating a software-level weakness that affects the device's ability to properly handle incoming network requests or maintain stable operation under normal conditions.
The technical nature of this vulnerability stems from inadequate input validation or improper resource handling within the affected NETGEAR devices' firmware implementations. When subjected to malformed network traffic or specific request patterns, these devices fail to properly process the incoming data and subsequently crash or become unresponsive. This behavior aligns with common denial of service attack patterns where an attacker can exploit implementation flaws to cause system instability or complete service interruption. The vulnerability likely resides in the device's web interface handling, network protocol processing, or other network services that manage external communications.
From an operational impact perspective, this vulnerability presents a significant risk to network availability and business continuity for organizations relying on these NETGEAR devices. The denial of service condition can occur without requiring authentication, making it particularly dangerous as any external attacker can potentially exploit it to disrupt network services. Network administrators may experience complete loss of access to affected devices, requiring manual intervention to restore functionality through firmware reinstallation or device reboot procedures. The widespread nature of affected models across different product lines suggests this is a fundamental flaw in the firmware architecture rather than an isolated incident.
The vulnerability can be classified under CWE-400 as an Uncontrolled Resource Consumption, representing a classic denial of service scenario where system resources are exhausted or improperly managed. From an ATT&CK framework perspective, this vulnerability maps to T1499.004 - Endpoint Denial of Service, as it targets network infrastructure devices to prevent legitimate users from accessing services. Organizations should prioritize immediate firmware updates to address this vulnerability, as the affected versions have been identified and patched by NETGEAR. Additionally, network segmentation and monitoring should be implemented to detect potential exploitation attempts, and regular vulnerability assessments should be conducted to identify other unpatched devices within the network infrastructure.
The remediation approach requires device administrators to upgrade to the latest firmware versions provided by NETGEAR, which contain patches addressing the specific denial of service conditions. The vendor has released version updates for each affected model, with specific version numbers indicating the minimum required firmware levels to achieve protection. Network security teams should implement a systematic approach to identify all affected devices within their infrastructure, particularly those that are publicly accessible or exposed to untrusted networks. Regular firmware update policies and network monitoring should be established to prevent similar vulnerabilities from being exploited in the future, as these devices may be targeted by automated scanning tools seeking to identify and exploit known vulnerabilities.