CVE-2018-21223 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, 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 flaw in NETGEAR networking equipment that exposes multiple device models to remote exploitation by unauthenticated attackers. The issue manifests in the web management interface of affected devices, where improper input validation allows attackers to craft malicious payloads that exceed allocated buffer space. This type of vulnerability falls under CWE-121, which describes stack-based buffer overflow conditions where insufficient bounds checking permits memory corruption. The vulnerability affects a wide range of NETGEAR routers and modems including the D3600, D6000, D7800, R6100, R7500 series, R9000, WNDR3700v4, WNDR4300, WNDR4300v2, WNDR4500v3, and WNR2000v5 models across various firmware versions. The buffer overflow condition occurs when the device processes HTTP requests containing oversized parameters or malformed input data in the web interface, potentially leading to arbitrary code execution or system crashes.
The operational impact of this vulnerability extends beyond simple device compromise as it enables attackers to gain unauthorized access to network infrastructure without requiring authentication credentials. Attackers can exploit this weakness to execute malicious code on the affected devices, potentially leading to complete network takeover, data exfiltration, or the installation of persistent backdoors. The vulnerability's exploitation capability aligns with ATT&CK technique T1059 which covers command and scripting interpreter usage, and T1071 which covers application layer protocol communication. Network attackers can leverage this vulnerability to establish persistent access points within corporate or residential networks, creating potential entry vectors for further lateral movement and reconnaissance activities. The unauthenticated nature of the attack means that any individual with access to the network can exploit this vulnerability without needing valid login credentials, making it particularly dangerous for widespread deployment.
Mitigation strategies for this vulnerability should prioritize immediate firmware updates from NETGEAR to address the underlying buffer overflow conditions. Organizations must conduct comprehensive inventory assessments to identify all affected device models within their network infrastructure and ensure timely patch deployment. Network segmentation and access control measures should be implemented to limit the potential impact of exploitation, while monitoring systems should be configured to detect anomalous traffic patterns that may indicate exploitation attempts. Security teams should also consider implementing network-based intrusion detection systems that can identify malicious HTTP requests targeting the vulnerable web interface components. The vulnerability demonstrates the importance of input validation and bounds checking in network device firmware, as outlined in industry security standards and practices. Regular security assessments and vulnerability scanning should be conducted to identify similar issues in other network equipment and ensure comprehensive protection against similar buffer overflow exploits. Organizations should also maintain updated network device inventories and establish protocols for rapid response to security advisories affecting their infrastructure.