CVE-2021-45630 in CBR40
Summary
by MITRE • 12/26/2021
Certain NETGEAR devices are affected by command injection by an unauthenticated attacker. This affects CBR40 before 2.5.0.24, CBR750 before 4.6.3.6, RBK752 before 3.2.17.12, RBR750 before 3.2.17.12, RBS750 before 3.2.17.12, RBK852 before 3.2.17.12, RBR850 before 3.2.17.12, and RBS850 before 3.2.17.12.
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Analysis
by VulDB Data Team • 12/28/2021
This vulnerability represents a critical command injection flaw in NETGEAR networking equipment that allows unauthenticated attackers to execute arbitrary commands on affected devices. The vulnerability affects multiple models within the CBR40, CBR750, RBK752, RBR750, RBS750, RBK852, RBR850, and RBS850 device families, with specific version ranges indicating the scope of impacted firmware releases. The flaw stems from inadequate input validation and sanitization within the device's web interface or management protocols, creating an attack vector that bypasses authentication mechanisms entirely.
The technical implementation of this vulnerability involves the improper handling of user-supplied input within command execution contexts. When an attacker submits malicious input through web forms, API endpoints, or other interface mechanisms, the system fails to properly sanitize or validate this input before incorporating it into system commands. This creates a direct injection pathway where attacker-controlled commands can be executed with the privileges of the affected service or system user. The vulnerability aligns with CWE-77 and CWE-89, which specifically address command injection and SQL injection flaws respectively, though the primary concern here is command execution rather than database manipulation.
The operational impact of this vulnerability extends far beyond simple unauthorized access, as it provides attackers with complete control over affected networking equipment. An unauthenticated attacker can leverage this vulnerability to gain root-level access to devices, potentially enabling network reconnaissance, traffic interception, man-in-the-middle attacks, or even lateral movement within the network infrastructure. The affected devices serve as critical network components that often operate with elevated privileges, making successful exploitation particularly dangerous for enterprise and home network environments. This vulnerability directly maps to ATT&CK technique T1059.001 for command and scripting interpreter and T1021.001 for remote services, representing both execution and lateral movement capabilities.
Mitigation strategies should prioritize immediate firmware updates from NETGEAR to the latest available versions that address this vulnerability. Network administrators should implement network segmentation to limit the attack surface and reduce the potential impact of successful exploitation. Additional protective measures include disabling unnecessary web management interfaces, implementing strong access controls, and monitoring network traffic for suspicious activity patterns. The vulnerability demonstrates the critical importance of proper input validation and the principle of least privilege in network infrastructure security, as it allows attackers to bypass traditional authentication mechanisms entirely. Organizations should also consider implementing network monitoring solutions that can detect anomalous command execution patterns and unauthorized device modifications.