CVE-2018-21221 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, and R9000 before 1.0.2.52.
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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 devices to remote exploitation without requiring authentication. The affected models include D3600, D6000, and R9000 routers, with specific firmware versions indicating the scope of impacted devices. The vulnerability stems from improper input validation within the device's web interface handling mechanisms, creating an exploitable condition that allows attackers to manipulate memory structures through crafted input parameters. Such buffer overflow conditions typically occur when programs write more data to a fixed-length buffer than it can accommodate, leading to memory corruption that can be leveraged for arbitrary code execution.
The technical implementation of this vulnerability involves the manipulation of network traffic directed to the affected devices, where unauthenticated attackers can craft malicious requests that trigger the buffer overflow condition. This flaw aligns with CWE-121, which describes stack-based buffer overflow conditions, and represents a classic example of how insufficient input validation can create persistent security weaknesses in network infrastructure devices. The attack surface is particularly concerning as it affects the web management interface of these routers, making the exploitation accessible to anyone who can reach the device's network address without requiring any credentials or prior access.
The operational impact of this vulnerability extends beyond simple denial of service scenarios, as it potentially enables complete compromise of affected devices. Once exploited, attackers could gain unauthorized access to the router's administrative functions, allowing them to modify network configurations, redirect traffic, or establish persistent backdoors. This represents a significant threat to network security as these devices typically serve as the primary gateway for network access, making them attractive targets for attackers seeking to establish long-term presence within networks. The vulnerability also aligns with ATT&CK technique T1059, which covers command and scripting interpreter usage, as successful exploitation could enable attackers to execute arbitrary commands on the affected devices.
Mitigation strategies for this vulnerability should prioritize immediate firmware updates from NETGEAR to address the specific buffer overflow conditions in the affected models. Network administrators should implement network segmentation and access control measures to limit exposure of these devices to untrusted networks, while also monitoring for unusual network traffic patterns that might indicate exploitation attempts. Additional protective measures include disabling unnecessary services, implementing network intrusion detection systems, and establishing regular vulnerability assessment procedures to identify similar issues in other network infrastructure components. The vulnerability also highlights the importance of secure coding practices and regular security testing of network equipment, particularly in critical infrastructure environments where device compromise could have severe operational consequences.