CVE-2021-45588 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-2021-45588 represents a critical command injection flaw affecting multiple NETGEAR router models including RBK752, RBR750, RBS750, RBK852, RBR850, and RBS850. This vulnerability resides in the web management interface of these devices and allows authenticated users to execute arbitrary commands on the underlying operating system. The flaw stems from insufficient input validation and sanitization within the device's web server implementation, creating a path for malicious command execution through specially crafted HTTP requests. The affected versions prior to 3.2.16.6 demonstrate a clear pattern of inadequate security controls in the device's user authentication and command processing mechanisms, making them susceptible to exploitation by attackers who have gained valid credentials.
The technical implementation of this vulnerability aligns with CWE-77 and CWE-94, which classify it as a command injection vulnerability and improper input validation respectively. Attackers exploiting this flaw can leverage the authenticated access to execute system commands with the privileges of the web server process, typically running with elevated permissions on the device. This command injection occurs when user-supplied parameters are directly incorporated into system commands without proper sanitization or encoding. The vulnerability is particularly concerning because it requires only authentication credentials, which are often easily obtained through social engineering, default credential exploitation, or other initial compromise techniques. The affected devices operate on embedded operating systems where command execution can lead to complete device compromise and potential network infiltration.
The operational impact of this vulnerability extends beyond individual device compromise to potential network-wide consequences. Once an attacker gains authenticated access to one device, they can execute commands that may include network reconnaissance, port scanning, or even command execution on other networked devices. The attack surface is further expanded when considering that these routers often serve as network gateways, providing access to internal network resources. The vulnerability creates opportunities for attackers to establish persistent access, modify network configurations, redirect traffic, or use the compromised devices as launching points for attacks against other systems. This aligns with ATT&CK techniques such as T1059 Command and Scripting Interpreter and T1021.001 Remote Services for lateral movement within the network infrastructure. The affected devices may also be used for botnet recruitment, DNS tunneling, or other malicious activities that leverage the router's network connectivity.
Mitigation strategies for CVE-2021-45588 primarily focus on immediate firmware updates to versions 3.2.16.6 or later, which address the command injection vulnerability through proper input validation and sanitization. Network administrators should implement strict access controls and monitor for unusual authentication patterns or command execution attempts. The vulnerability highlights the importance of secure coding practices and input validation in embedded systems, particularly those handling user-provided data in web interfaces. Organizations should also consider implementing network segmentation to limit the potential impact of device compromise and establish monitoring protocols for detecting unauthorized command execution. Regular security assessments of network infrastructure and mandatory firmware update policies are essential to prevent exploitation of similar vulnerabilities. The incident underscores the necessity of maintaining up-to-date security controls and proper access management in networked environments where device authentication is the primary security boundary.