CVE-2021-38513 in RBK852
Summary
by MITRE • 08/11/2021
Certain NETGEAR devices are affected by authentication bypass. This affects RBK852 before 3.2.10.11, RBR850 before 3.2.10.11, RBS850 before 3.2.10.11, CBR40 before 2.5.0.10, EAX20 before 1.0.0.48, MK62 before 1.0.6.110, MR60 before 1.0.6.110, MS60 before 1.0.6.110, RBK752 before 3.2.10.10, RBR750 before 3.2.10.10, and RBS750 before 3.2.10.10.
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Analysis
by VulDB Data Team • 08/16/2021
The vulnerability identified as CVE-2021-38513 represents a critical authentication bypass flaw affecting multiple NETGEAR networking devices across various product lines including routers and access points. This issue stems from improper validation of authentication credentials within the device's web interface, allowing unauthorized users to bypass the standard login process and gain administrative access to affected systems. The vulnerability impacts a wide range of devices including the RBK852, RBR850, RBS850, CBR40, EAX20, MK62, MR60, MS60, RBK752, RBR750, and RBS750 models, with specific version constraints indicating that firmware versions prior to the mentioned thresholds remain susceptible to exploitation. The authentication bypass vulnerability falls under the CWE-287 category of Improper Authentication, which is a fundamental security weakness that allows attackers to assume the identity of legitimate users without proper credentials.
The technical exploitation of this vulnerability occurs through manipulation of the device's web-based management interface where the authentication mechanism fails to properly validate user credentials or maintain session state. Attackers can leverage this flaw to access administrative functions without providing valid login information, potentially gaining complete control over the affected networking equipment. The impact extends beyond simple unauthorized access as it enables attackers to modify network configurations, change administrator passwords, install malicious firmware, or redirect network traffic through the compromised device. This represents a significant risk to network security since routers and access points serve as critical infrastructure components that control network access and traffic flow. The vulnerability's persistence across multiple device families suggests a systemic issue in the firmware implementation rather than isolated component failures.
From an operational perspective, the exploitation of this authentication bypass vulnerability can lead to severe consequences including complete network compromise, data exfiltration, man-in-the-middle attacks, and disruption of network services. The affected devices typically serve as gateways between internal networks and external internet connections, making them prime targets for attackers seeking to establish persistent access points within corporate or home networks. The vulnerability's impact is particularly concerning because it allows attackers to remain undetected while performing administrative functions, potentially leading to long-term network infiltration. Security analysts should consider this vulnerability in the context of the MITRE ATT&CK framework, specifically under the T1078 technique for Valid Accounts and T1566 for Phishing, as attackers may use this bypass to establish persistent access after initial compromise through other means.
The recommended mitigation strategy involves immediate firmware updates from NETGEAR to versions 3.2.10.11 or later for affected RBK852, RBR850, RBS850, 3.2.10.10 for affected RBK752, RBR750, and RBS750, and appropriate versions for the other affected models. Organizations should also implement network segmentation to limit the potential impact of compromised devices and consider disabling unnecessary web management interfaces when not actively required. Additional protective measures include implementing strong network access controls, monitoring for unauthorized administrative access attempts, and maintaining comprehensive network inventory to identify all potentially affected devices. The vulnerability underscores the importance of regular firmware updates and proper security configuration management for network infrastructure devices, as these devices often operate with elevated privileges and control critical network functions.