CVE-2018-21201 in D6100
Summary
by MITRE
Certain NETGEAR devices are affected by a stack-based buffer overflow by an authenticated user. This affects D6100 before 1.0.0.57, R6100 before 1.0.1.20, R7800 before 1.0.2.40, R9000 before 1.0.2.52, WNDR3700v4 before 1.0.2.92, WNDR4300 before 1.0.2.94, WNDR4300v2 before 1.0.0.50, WNDR4500v3 before 1.0.0.50, and WNR2000v5 before 1.0.0.62.
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Analysis
by VulDB Data Team • 06/03/2024
This vulnerability represents a critical stack-based buffer overflow flaw in NETGEAR router firmware that allows authenticated users to execute arbitrary code on affected devices. The issue stems from improper input validation within the web management interface of multiple router models, creating a condition where maliciously crafted input can overwrite adjacent memory locations on the stack. Such vulnerabilities fall under CWE-121 stack-based buffer overflow category, which is classified as a high-risk security weakness in software systems. The affected devices operate with firmware versions prior to specific patches, indicating that this vulnerability has been present in production systems for extended periods without proper mitigation.
The technical exploitation of this vulnerability requires an authenticated user to submit specially crafted input to the router's web interface, typically through HTTP requests or form submissions. When the vulnerable firmware processes this input without proper bounds checking, it allows the attacker to overwrite return addresses, function pointers, or other critical stack data structures. This type of attack aligns with ATT&CK technique T1059.007 for command and scripting interpreter and T1068 for exploit for privilege escalation. The buffer overflow can potentially lead to complete system compromise, allowing attackers to gain root access to the device and execute arbitrary commands with full administrative privileges.
The operational impact of this vulnerability extends beyond simple device compromise, as these routers serve as critical network infrastructure components. Compromised routers can enable attackers to perform man-in-the-middle attacks, redirect traffic, install malware, or use the device as a pivot point for attacking internal network resources. The vulnerability affects multiple router models including the D6100, R6100, R7800, R9000, and various WNDR and WNR series devices, indicating a widespread exposure across NETGEAR's product portfolio. Network administrators face the challenge of identifying and patching numerous devices across their infrastructure, as these routers are often deployed in both residential and enterprise environments where they control network access and security policies.
Mitigation strategies should prioritize immediate firmware updates from NETGEAR to address the specific buffer overflow conditions. Organizations must conduct comprehensive inventory assessments to identify all affected devices and ensure timely patch deployment across their network infrastructure. Additional defensive measures include implementing network segmentation to limit the impact of potential compromises, monitoring for unusual network traffic patterns that may indicate exploitation attempts, and enforcing strong authentication mechanisms to prevent unauthorized access to router management interfaces. The vulnerability also highlights the importance of secure coding practices and regular security assessments in embedded firmware development, particularly for network infrastructure devices that are often deployed with minimal security oversight.