CVE-2021-45593 in RBR20
Summary
by MITRE • 12/26/2021
Certain NETGEAR devices are affected by command injection by an authenticated user. This affects RBR20 before 2.7.3.22, RBR40 before 2.7.3.22, RBR50 before 2.7.2.102, RBS20 before 2.7.3.22, RBS40 before 2.7.3.22, RBR50 before 2.7.2.102, RBK20 before 2.7.3.22, RBK40 before 2.7.3.22, and RBK50 before 2.7.2.102.
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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 authenticated attackers to execute arbitrary commands on affected devices. The issue stems from improper input validation within the web interface of various RBR and RBS series routers and access points, creating a pathway for privilege escalation through authenticated user sessions. The affected models span multiple device families including RBR20, RBR40, RBR50, RBS20, RBS40, RBK20, RBK40, and RBK50, with specific firmware versions prior to 2.7.3.22 or 2.7.2.102 being vulnerable. This vulnerability directly maps to CWE-77 Command Injection, which is classified under the CWE top 25 most dangerous software weaknesses and represents a significant security risk in network infrastructure devices.
The technical exploitation occurs when an authenticated user submits malicious input through web interface parameters that are subsequently processed without proper sanitization. Attackers can leverage this flaw to inject operating system commands that execute with the privileges of the web server process, typically running with elevated permissions on the device. This allows for complete compromise of the affected network equipment, enabling attackers to modify device configurations, install malicious firmware, redirect traffic, or establish persistent access points. The vulnerability is particularly concerning because it requires only authentication credentials, making it exploitable by insiders or attackers who have gained initial access through other means such as credential theft or social engineering attacks.
The operational impact of this vulnerability extends beyond simple device compromise to potentially enable broader network infiltration and lateral movement within corporate environments. Network administrators who rely on these devices for critical infrastructure functions face significant risk of unauthorized access to their network traffic, configuration data, and potentially sensitive business information. The vulnerability creates a persistent backdoor that could remain undetected for extended periods, as command injection attacks often leave minimal forensic traces. This aligns with ATT&CK technique T1059.001 Command and Scripting Interpreter, where adversaries use legitimate system tools to execute commands, and T1566.001 Phishing, as initial access often occurs through credential compromise. Organizations using these devices face potential compliance violations and regulatory scrutiny if their network infrastructure is compromised.
Mitigation strategies should prioritize immediate firmware updates to versions 2.7.3.22 or 2.7.2.102 for affected models, as provided by NETGEAR through their security advisory channels. Network segmentation and access controls should be implemented to limit the attack surface, while monitoring systems should be deployed to detect anomalous command execution patterns. Regular security audits and vulnerability assessments should include testing for similar injection vulnerabilities in network infrastructure devices. Network administrators should also implement multi-factor authentication for administrative access and establish robust network monitoring to detect unauthorized configuration changes. The vulnerability highlights the importance of secure coding practices and input validation in embedded systems, particularly in network infrastructure devices where a single flaw can compromise entire network domains. Organizations should conduct thorough risk assessments to determine if their network architecture is sufficiently protected against such attacks and consider implementing network intrusion detection systems to identify potential exploitation attempts.