CVE-2018-21214 in D3600
Summary
by MITRE
Certain NETGEAR devices are affected by a buffer overflow by an unauthenticated attacker. This affects D3600 before 1.0.0.67, D6000 before 1.0.0.67, EX2700 before 1.0.1.28, R6100 before 1.0.1.20, R7500v2 before 1.0.3.24, R9000 before 1.0.2.52, WN2000RPTv3 before 1.0.1.20, WN3000RPv3 before 1.0.2.50, and WN3100RPv2 before 1.0.0.56.
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Analysis
by VulDB Data Team • 06/04/2024
This vulnerability represents a critical buffer overflow flaw in NETGEAR networking equipment that exposes multiple device models to remote exploitation without authentication requirements. The affected devices include various router and wireless access point models spanning different product lines including the D3600, D6000, EX2700, R6100, R7500v2, R9000, WN2000RPTv3, WN3000RPv3, and WN3100RPv2 series. The vulnerability exists in the web interface handling of HTTP requests, specifically in the processing of user-supplied input that is not properly validated or bounded before being copied into fixed-size buffers. This allows an attacker to craft malicious HTTP requests that can overflow the allocated buffer space and potentially execute arbitrary code on the affected devices. The impact extends beyond simple denial of service as the vulnerability can be exploited remotely by unauthenticated attackers, making it particularly dangerous for network infrastructure devices that are often accessible from the internet. The vulnerability affects firmware versions prior to specific patches, with each model requiring different minimum firmware versions to remediate the issue. This type of buffer overflow vulnerability is classified under CWE-121 as a stack-based buffer overflow, which represents a well-known and dangerous class of software defects that can lead to complete system compromise. The attack surface is particularly concerning given that these devices are commonly deployed in residential and small office environments where they may be directly exposed to external network traffic without proper network segmentation or firewall protection. According to ATT&CK framework, this vulnerability maps to T1210 - Exploitation of Remote Services, where adversaries can leverage unauthenticated access to device management interfaces to gain unauthorized control. The vulnerability's severity is amplified by the fact that these devices typically run with elevated privileges and have direct access to network traffic, potentially allowing attackers to establish persistent backdoors or redirect network traffic. The lack of authentication requirements makes this vulnerability particularly attractive to automated exploitation tools and makes it difficult to detect through traditional network monitoring. Organizations should immediately assess their network infrastructure to identify all affected NETGEAR devices and apply the vendor-provided firmware updates. Network segmentation and firewall rules should be implemented to restrict access to device management interfaces, while monitoring should be enhanced to detect unusual traffic patterns that might indicate exploitation attempts. The vulnerability highlights the importance of secure coding practices in embedded systems and demonstrates how seemingly minor input validation flaws can lead to complete system compromise. This issue represents a classic example of how legacy embedded systems often lack proper memory safety mechanisms that are standard in modern software development practices, making them particularly susceptible to buffer overflow attacks that have been well understood and mitigated in other software domains for decades.