CVE-2018-21219 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, D6100 before 1.0.0.56, D7800 before 1.0.1.30, R6100 before 1.0.1.20, R7500 before 1.0.0.118, R7500v2 before 1.0.3.24, R9000 before 1.0.2.52, WNDR3700v4 before 1.0.2.96, WNDR4300 before 1.0.2.98, 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 • 06/04/2024
This vulnerability represents a critical buffer overflow condition that affects multiple NETGEAR router models, creating a significant security risk for network infrastructure. The flaw exists within the web interface handling of certain NETGEAR devices, specifically targeting the D3600, D6000, D6100, D7800, R6100, R7500, R7500v2, R9000, WNDR3700v4, WNDR4300, WNDR4300v2, WNDR4500v3, and WNR2000v5 models. The vulnerability allows unauthenticated attackers to exploit the buffer overflow through crafted input parameters, potentially leading to remote code execution and complete system compromise.
The technical implementation of this vulnerability stems from improper input validation within the device's web management interface. When processing HTTP requests containing overly long strings in specific parameters, the system fails to properly bounds-check the input data before copying it into fixed-size buffers. This classic buffer overflow condition enables attackers to overwrite adjacent memory locations, potentially including return addresses, function pointers, or other critical control data. The vulnerability is particularly dangerous because it requires no authentication, making it accessible to anyone on the network or even remotely if the device exposes the web interface to the internet.
From an operational security perspective, this vulnerability creates multiple attack vectors that can be exploited by threat actors with varying skill levels. The impact extends beyond simple system compromise to include complete network takeover, data exfiltration, and potential use as a pivot point for lateral movement within corporate networks. Attackers can leverage this vulnerability to gain root-level access to affected devices, enabling them to modify firmware, redirect traffic, or establish persistent backdoors. The widespread deployment of these affected models across both residential and enterprise networks amplifies the potential impact, as many organizations may not be aware of their exposure to this vulnerability.
The exploitation of this buffer overflow aligns with attack patterns documented in the MITRE ATT&CK framework, particularly under the techniques of remote code execution and privilege escalation. This vulnerability directly maps to CWE-121, which describes stack-based buffer overflow conditions, and CWE-122, which covers heap-based buffer overflow scenarios. Network defenders should consider implementing network segmentation to isolate affected devices, monitoring for unusual traffic patterns that may indicate exploitation attempts, and maintaining up-to-date threat intelligence feeds that track exploitation of this specific vulnerability. Additionally, the affected devices should be immediately updated to the latest firmware versions provided by NETGEAR, as these releases contain the necessary patches to address the buffer overflow conditions and prevent exploitation by unauthorized parties. Organizations should also consider implementing network-based intrusion detection systems that can identify and block malicious traffic patterns associated with this vulnerability.