CVE-2021-45585 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-2021-45585 represents a critical command injection flaw affecting multiple NETGEAR router models including RBK752, RBR750, RBS750, RBK852, RBR850, and RBS850. This vulnerability allows authenticated attackers to execute arbitrary commands on affected devices through specially crafted inputs. The flaw stems from insufficient input validation and sanitization within the device's web interface, which processes user-supplied data without proper escaping or filtering mechanisms. The affected firmware versions prior to 3.2.16.6 demonstrate a clear failure in implementing proper security controls for user input handling.
This command injection vulnerability operates at the application layer and directly impacts the device's web administration interface. When an authenticated user submits malicious input through web forms or API endpoints, the system fails to properly validate or sanitize the data before incorporating it into system commands. The vulnerability is classified as CWE-77 according to the Common Weakness Enumeration catalog, which specifically addresses command injection flaws. Attackers can exploit this weakness to execute arbitrary shell commands with the privileges of the web server process, potentially leading to complete device compromise.
The operational impact of this vulnerability extends beyond simple unauthorized command execution. An authenticated attacker with access to the device's administrative interface can leverage this flaw to gain persistent access, modify device configurations, redirect traffic, or establish backdoors for future exploitation. The affected devices operate in network infrastructure roles, making them attractive targets for attackers seeking to establish persistent footholds within network environments. This vulnerability also aligns with ATT&CK technique T1059.001 for command and scripting interpreter, as it enables execution of system commands through the web interface.
Mitigation strategies for CVE-2021-45585 primarily focus on firmware updates and access controls. NETGEAR has released firmware versions 3.2.16.6 and later that address this vulnerability through proper input validation and sanitization mechanisms. Organizations should immediately upgrade all affected devices to the patched firmware versions. Additional protective measures include implementing network segmentation, restricting administrative access to trusted networks, enforcing strong authentication mechanisms, and monitoring for unusual administrative activities. The vulnerability also highlights the importance of input validation in web applications and demonstrates how seemingly minor flaws in user interface handling can result in severe security consequences.