CVE-2021-45589 in RBK752
Summary
by MITRE • 12/26/2021
Certain NETGEAR devices are affected by command injection by an authenticated user. This affects RBK752 before 3.2.16.6, RBR750 before 3.2.16.6, RBS750 before 3.2.16.6, RBK852 before 3.2.16.6, RBR850 before 3.2.16.6, and RBS850 before 3.2.16.6.
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Analysis
by VulDB Data Team • 12/28/2021
The vulnerability identified as CVE-2021-45589 represents a critical command injection flaw affecting multiple NETGEAR router models within the RBK and RBR series. This security weakness allows authenticated attackers to execute arbitrary commands on affected devices, potentially compromising the entire network infrastructure. The vulnerability specifically impacts firmware versions prior to 3.2.16.6 across several router models including RBK752, RBR750, RBS750, RBK852, RBR850, and RBS850. The affected devices operate within enterprise and small office environments where network security is paramount, making this vulnerability particularly dangerous as it provides attackers with elevated privileges to manipulate network traffic and potentially gain further access to connected systems.
The technical implementation of this command injection vulnerability stems from insufficient input validation and sanitization within the device's web interface or management protocols. When authenticated users submit malicious input through specific parameters or API endpoints, the system fails to properly sanitize or escape these inputs before processing them. This allows attackers to inject operating system commands that are subsequently executed with the privileges of the web application or service handling the request. The vulnerability aligns with CWE-77 which specifically addresses command injection flaws, and represents a classic example of how inadequate input validation can lead to arbitrary code execution. The attack vector typically involves exploiting web-based management interfaces where users can submit configuration parameters or diagnostic commands, with the malicious input being processed without proper security controls.
The operational impact of this vulnerability extends beyond simple unauthorized access, as it enables attackers to manipulate network configurations, redirect traffic, or establish persistent backdoors within the affected network. An authenticated attacker with access to the device's management interface can leverage this vulnerability to execute commands that may include network reconnaissance, port scanning, or even privilege escalation to administrative levels. The implications are particularly severe in enterprise environments where these routers serve as network gateways, potentially allowing attackers to compromise entire network segments or establish lateral movement opportunities. This vulnerability also aligns with several ATT&CK techniques including T1059 for command and script interpreter and T1021 for remote services, demonstrating how the flaw can be exploited to establish persistent access and maintain control over network infrastructure.
Mitigation strategies for CVE-2021-45589 primarily focus on firmware updates and network segmentation. Device administrators should immediately upgrade all affected NETGEAR routers to firmware version 3.2.16.6 or later, which contains patches addressing the command injection vulnerability. Additionally, network administrators should implement strict access controls and monitor for unusual management interface activity that might indicate exploitation attempts. The vulnerability also highlights the importance of network segmentation and implementing principle of least privilege for administrative access. Organizations should consider disabling unnecessary management interfaces and implementing multi-factor authentication for administrative access to reduce the attack surface. Security monitoring should include detection of suspicious command execution patterns and anomalous network behavior that could indicate exploitation of this vulnerability, as the attack may not be immediately obvious to network administrators.