CVE-2021-45581 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 CVE-2021-45581 represents a critical command injection flaw affecting multiple NETGEAR router models including RBK752, RBR750, RBS750, RBK852, RBR850, and RBS850. This vulnerability stems from insufficient input validation within the device management interfaces, allowing authenticated users to execute arbitrary commands on the affected devices. The flaw specifically impacts firmware versions prior to 3.2.16.6, indicating that devices running these older versions remain exposed to potential exploitation. The command injection vulnerability enables attackers who have gained authentication credentials to escalate their privileges and execute malicious code directly on the router's operating system.
The technical implementation of this vulnerability involves the improper handling of user-supplied input within the web administration interface of these network devices. When authenticated users submit specific input parameters to the device management functions, the system fails to properly sanitize or validate the input before processing it within the command execution context. This allows attackers to inject malicious commands that are subsequently executed with the privileges of the web server process, which typically operates with administrative privileges on the device. The vulnerability falls under CWE-77 which specifically addresses command injection flaws in software applications, and aligns with ATT&CK technique T1059.001 for command and script injection. The affected devices are particularly vulnerable because they process user input without adequate sanitization, creating an attack surface where legitimate administrative functions can be subverted for malicious purposes.
The operational impact of this vulnerability extends beyond simple unauthorized access to encompass full device compromise and potential network infiltration. An authenticated attacker can leverage this vulnerability to gain complete control over the affected routers, potentially enabling them to modify network configurations, redirect traffic, establish backdoors, or use the devices as launching points for attacks against other network resources. The implications are particularly severe for enterprise environments where these routers may serve as critical network infrastructure components, as compromised devices can provide attackers with persistent access to internal networks and facilitate lateral movement. Additionally, the vulnerability affects devices that are commonly deployed in residential and small office environments, where network security awareness may be limited, increasing the likelihood of successful exploitation and prolonged compromise. Organizations using these affected devices face significant risk of data breaches, network disruption, and potential regulatory compliance violations.
Mitigation strategies for CVE-2021-45581 primarily focus on firmware updates and network segmentation. The most effective immediate solution involves upgrading all affected NETGEAR devices to firmware version 3.2.16.6 or later, which contains patches addressing the command injection vulnerability. Network administrators should also implement strict access controls and authentication measures, ensuring that only authorized personnel have access to the device management interfaces. Additional protective measures include network segmentation to limit the potential impact of device compromise, implementing intrusion detection systems to monitor for suspicious command execution patterns, and conducting regular security assessments of network infrastructure. Organizations should also consider implementing network access control policies that restrict administrative access to these devices from untrusted networks, and establish monitoring procedures to detect unauthorized configuration changes or unusual network traffic patterns that may indicate exploitation attempts. The vulnerability highlights the importance of maintaining up-to-date firmware and implementing defense-in-depth strategies to protect network infrastructure from authenticated attack vectors.