CVE-2021-45632 in CBR750
Summary
by MITRE • 12/26/2021
Certain NETGEAR devices are affected by command injection by an unauthenticated attacker. This affects 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
The vulnerability identified as CVE-2021-45632 represents a critical command injection flaw affecting multiple NETGEAR router models including CBR750, RBK752, RBR750, RBS750, RBK852, RBR850, and RBS850. This vulnerability allows unauthenticated attackers to execute arbitrary commands on affected devices, fundamentally compromising the security posture of network infrastructure. The flaw exists in the web interface handling of device management commands, where input validation is insufficient to prevent malicious command injection attempts. The affected versions prior to 4.6.3.6 and 3.2.17.12 demonstrate a persistent weakness in the device firmware's security architecture that enables remote code execution without requiring authentication credentials.
This command injection vulnerability operates at the application layer and directly violates multiple security principles outlined in the CWE database under CWE-77 and CWE-88 categories. The technical implementation flaw stems from improper sanitization of user-supplied input within the web management interface, specifically in parameters handling commands for system operations. Attackers can exploit this by crafting malicious payloads that bypass authentication mechanisms and inject system commands directly into the device's processing pipeline. The vulnerability's impact extends beyond simple unauthorized access to include complete system compromise, data exfiltration, and potential lateral movement within network environments.
The operational impact of this vulnerability is severe for organizations relying on affected NETGEAR devices as network gateways and routers. Unauthenticated command injection enables attackers to gain complete administrative control over affected devices, potentially leading to man-in-the-middle attacks, DNS hijacking, traffic interception, and network disruption. The vulnerability affects enterprise and small business networks simultaneously, as these devices often serve as primary internet gateways without proper network segmentation. According to ATT&CK framework categorization under T1059.001 for command and scripting interpreter, this vulnerability enables adversaries to execute malicious commands remotely, while T1071.001 for application layer protocol provides the attack vector through web interface exploitation.
Mitigation strategies for CVE-2021-45632 primarily focus on immediate firmware updates to versions 4.6.3.6 and 3.2.17.12 or later, which contain patches addressing the command injection flaw. Network administrators should also implement network segmentation to limit access to affected devices, disable unnecessary services, and monitor for suspicious network traffic patterns. Additional protective measures include implementing web application firewalls, restricting remote management access, and conducting thorough network vulnerability assessments. The vulnerability highlights the importance of secure coding practices and input validation in network infrastructure devices, as outlined in OWASP Top 10 and NIST cybersecurity guidelines for embedded systems security. Organizations should also consider implementing intrusion detection systems to monitor for exploitation attempts and establish incident response procedures for rapid remediation when such vulnerabilities are discovered.