CVE-2021-38518 in RAX200
Summary
by MITRE • 08/11/2021
Certain NETGEAR devices are affected by command injection by an authenticated user. This affects RAX200 before 1.0.4.120, RAX75 before 1.0.4.120, RAX80 before 1.0.4.120, RBK852 before 3.2.17.12, RBR850 before 3.2.17.12, and RBS850 before 3.2.17.12.
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Analysis
by VulDB Data Team • 09/18/2021
This vulnerability represents a critical command injection flaw in NETGEAR wireless routers and access points that allows authenticated attackers to execute arbitrary commands on affected devices. The vulnerability affects multiple models including RAX200, RAX75, RAX80, RBK852, RBR850, and RBS850 series devices, with specific versions prior to 1.0.4.120 for RAX models and 3.2.17.12 for RBK, RBR, and RBS models. The flaw stems from inadequate input validation within the device's web interface and command processing mechanisms, enabling an authenticated user to inject malicious commands that are then executed with the privileges of the web server process. This represents a significant security weakness that can be exploited by attackers who have already gained access to the device through legitimate authentication methods.
The technical exploitation of this vulnerability occurs through the manipulation of input parameters within the device's web management interface. When an authenticated user submits crafted input to specific parameters, the device fails to properly sanitize or validate the input before executing commands, leading to a command injection attack. The vulnerability is classified as CWE-77 according to the Common Weakness Enumeration catalog, which specifically addresses command injection flaws that allow attackers to execute arbitrary commands on the target system. The affected devices typically process user input through web forms or API endpoints without adequate sanitization, creating an environment where malicious payloads can be executed with the privileges of the web server process. This type of vulnerability is particularly dangerous because it requires only authentication, which can often be obtained through social engineering, default credentials, or other initial compromise techniques.
The operational impact of this vulnerability extends beyond simple command execution, as it can enable full system compromise and persistent access to affected networks. An attacker who successfully exploits this vulnerability can gain complete control over the affected device, potentially using it as a pivot point to attack other devices within the network. The compromised device may be used to establish persistent backdoors, redirect traffic, or serve as a command and control node for further attacks. This vulnerability particularly affects enterprise and home networks where these devices serve as primary gateways, potentially allowing attackers to disrupt network services or gain unauthorized access to sensitive data. The impact is amplified by the fact that these devices often have elevated privileges and are typically located in network perimeters where they can provide access to internal systems.
Mitigation strategies for this vulnerability should focus on immediate firmware updates from NETGEAR to address the command injection flaw, along with network segmentation to limit the potential impact of compromise. Organizations should implement strict access controls and authentication mechanisms to reduce the likelihood of unauthorized access to device management interfaces. Network monitoring should be enhanced to detect unusual command execution patterns or traffic anomalies that may indicate exploitation attempts. Security teams should also consider implementing web application firewalls to filter potentially malicious input before it reaches the device's command processing components. The vulnerability demonstrates the importance of proper input validation and output encoding in web applications, as outlined in the OWASP Top Ten and MITRE ATT&CK framework's application layer attacks category, where command injection is classified as a technique for executing arbitrary code. Regular security assessments and vulnerability scanning should be conducted to identify similar flaws in other network infrastructure components, as this vulnerability type remains prevalent in embedded systems and network devices.