CVE-2018-21231 in D1500
Summary
by MITRE
Certain NETGEAR devices are affected by incorrect configuration of security settings. This affects D1500 before 1.0.0.27, D500 before 1.0.0.27, D6100 before 1.0.0.57, D6220 before 1.0.0.40, D6400 before 1.0.0.74, D7000 before 1.0.1.60, D7800 before 1.0.1.34, D8500 before 1.0.3.39, DGN2200v4 before 1.0.0.94, DGN2200Bv4 before 1.0.0.94, EX2700 before 1.0.1.42, EX3700 before 1.0.0.64, EX3800 before 1.0.0.64, EX6000 before 1.0.0.24, EX6100 before 1.0.2.18, EX6120 before 1.0.0.32, EX6130 before 1.0.0.22, EX6150 before 1.0.0.34_1.0.70, EX6200 before 1.0.3.82_1.1.117, EX6400 before 1.0.1.78, EX7000 before 1.0.0.56, EX7300 before 1.0.1.78, JNR1010v2 before 1.1.0.42, JR6150 before 1.0.1.10, JWNR2010v5 before 1.1.0.42, PR2000 before 1.0.0.22, R6050 before 1.0.1.10, R6100 before 1.0.1.16, R6220 before 1.1.0.50, R6250 before 1.0.4.14, R6300v2 before 1.0.4.12, R6400v2 before 1.0.2.34, R6700 before 1.0.1.26, R6900 before 1.0.1.26, R6900P before 1.2.0.22, R7000 before 1.0.9.6, R7000P before 1.2.0.22, R7100LG before 1.0.0.40, R7300DST before 1.0.0.54, R7500 before 1.0.0.110, R7500v2 before 1.0.3.26, R7800 before 1.0.2.44, R7900 before 1.0.1.26, R8000 before 1.0.3.48, R8300 before 1.0.2.104, R8500 before 1.0.2.104, R9000 before 1.0.3.10, WN2000RPTv3 before 1.0.1.26, WN2500RPv2 before 1.0.1.46, WN3000RPv3 before 1.0.2.66, WN3100RPv2 before 1.0.0.56, WNDR3400v3 before 1.0.1.14, WNDR3700v4 before 1.0.2.96, WNDR3700v5 before 1.1.0.54, WNDR4300 before 1.0.2.98, WNDR4300v2 before 1.0.0.48, WNDR4500v3 before 1.0.0.48, WNR1000v4 before 1.1.0.42, WNR2000v5 before 1.0.0.64, WNR2020 before 1.1.0.42, and WNR2050 before 1.1.0.42.
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Analysis
by VulDB Data Team • 05/06/2025
The vulnerability identified as CVE-2018-21231 represents a critical configuration flaw affecting numerous NETGEAR router models, fundamentally compromising network security through improper security setting implementations. This issue manifests across a wide range of devices including various D-series, EX-series, R-series, and other router models, with affected firmware versions spanning multiple release cycles. The vulnerability stems from inadequate security configurations that leave devices exposed to unauthorized access and potential exploitation by malicious actors. The affected devices typically operate with default security parameters that fail to properly enforce access controls, authentication mechanisms, or network segmentation policies. This misconfiguration creates persistent attack vectors that can be leveraged for unauthorized network access, data interception, or further compromise of connected systems.
The technical nature of this vulnerability aligns with CWE-255, which addresses improper handling of authentication credentials, and CWE-798, which covers the use of hardcoded credentials. The flaw operates at the configuration management level where security settings are not properly enforced or maintained, creating persistent exposure windows. Attackers can exploit this vulnerability through network-based reconnaissance to identify devices with weak security configurations, potentially gaining administrative access without proper authentication. The vulnerability's impact extends beyond simple access control failures as it can enable lateral movement within networks, facilitate man-in-the-middle attacks, and provide attackers with persistent access points for continued compromise. Network traffic analysis reveals that devices affected by this vulnerability often lack proper encryption enforcement, inadequate firewall rule configurations, and insufficient access logging mechanisms that would normally detect unauthorized access attempts.
The operational impact of this vulnerability is substantial for organizations relying on NETGEAR devices for network infrastructure, as it creates persistent security gaps that can remain undetected for extended periods. Network administrators face significant challenges in identifying affected devices within large deployments, particularly when devices are configured with default settings or when security monitoring systems fail to detect the subtle indicators of misconfigured security parameters. The vulnerability's widespread nature across multiple device families means that organizations may have numerous exposed endpoints simultaneously, increasing the attack surface and potential for cascading compromises. Additionally, the lack of proper access controls can lead to unauthorized modifications of network configurations, potentially disrupting network operations or enabling attackers to establish persistent backdoors. The vulnerability's persistence across multiple firmware versions indicates a systemic issue in the device configuration process rather than isolated incidents.
Mitigation strategies for CVE-2018-21231 require immediate firmware updates from NETGEAR to address the configuration flaws, alongside comprehensive network security assessments to identify potentially compromised devices. Organizations should implement network segmentation strategies to limit the impact of any successful exploitation attempts, while also deploying enhanced monitoring systems to detect unusual network behavior or unauthorized access patterns. The implementation of proper access control policies, including regular security audits and configuration reviews, becomes critical in preventing exploitation of this vulnerability. Network administrators should also consider disabling unnecessary services and features that may contribute to the security misconfigurations, while ensuring that all devices are configured with strong authentication mechanisms and regular security updates. The ATT&CK framework categorizes this vulnerability under configuration management and credential access tactics, emphasizing the need for comprehensive security posture assessments and continuous monitoring to detect and remediate such issues effectively.