CVE-2021-45583 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.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 12/28/2021
This vulnerability represents a critical command injection flaw in NETGEAR router firmware that allows authenticated users to execute arbitrary commands on affected devices. The vulnerability affects multiple models within the RBK and RBR series, specifically those running firmware versions prior to 3.2.16.6. The issue stems from insufficient input validation and sanitization within the device's web interface, where user-supplied parameters are directly incorporated into system commands without proper escaping or filtering mechanisms. This type of vulnerability falls under CWE-77 which specifically addresses command injection flaws in software systems.
The technical exploitation of this vulnerability occurs when an authenticated user submits malicious input through the web administration interface, which is then processed by the device's command execution engine. The affected devices lack proper parameter sanitization, allowing attackers to inject operating system commands that are subsequently executed with the privileges of the web server process. This creates a significant attack surface where an authenticated user can potentially gain unauthorized access to the device's underlying operating system, modify configurations, or even escalate privileges to root level access depending on the device architecture and implementation details.
From an operational perspective, this vulnerability poses severe risks to network security infrastructure as it enables attackers who have obtained valid credentials to escalate their privileges and compromise the entire network. The impact extends beyond individual device compromise since routers serve as critical network gateways and often have elevated privileges within the network ecosystem. Attackers could leverage this vulnerability to redirect traffic, install malicious firmware, or establish persistent backdoors that could remain undetected for extended periods. The vulnerability is particularly concerning because it requires only authentication credentials, making it accessible to anyone with legitimate access to the device's web interface, which could include employees, contractors, or other authorized personnel.
The mitigation strategy for this vulnerability involves immediate firmware updates to versions 3.2.16.6 or later, which contain proper input validation and sanitization mechanisms. Network administrators should also implement strict access controls and monitor for unusual administrative activities that might indicate exploitation attempts. Additionally, organizations should consider implementing network segmentation and monitoring solutions to detect potential command execution activities on their network infrastructure. This vulnerability aligns with ATT&CK technique T1059 which covers command and scripting interpreter, and represents a classic example of how authenticated access can be leveraged to achieve privilege escalation and persistent access within network environments. The affected devices should be isolated from critical network segments until proper patches are applied and comprehensive security assessments have been completed.