CVE-2021-45587 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-2021-45587 represents a critical command injection flaw affecting multiple NETGEAR router models including RBK752, RBR750, RBS750, RBK852, RBR850, and RBS850. This issue stems from insufficient input validation within the web interface of these devices, allowing authenticated users to execute arbitrary commands on the underlying operating system. The vulnerability specifically impacts firmware versions prior to 3.2.16.6, indicating that devices running older software versions remain exposed to this security risk. The affected models represent a range of NETGEAR routers that are commonly deployed in both residential and small office environments, making this vulnerability particularly concerning from a widespread impact perspective.
The technical implementation of this command injection vulnerability occurs through the manipulation of parameters within the web administration interface. When an authenticated user submits malicious input to specific parameters, the system fails to properly sanitize or validate the input before processing it within the command execution context. This allows attackers to inject shell commands that are then executed with the privileges of the web server process, typically running with elevated permissions on the device. The vulnerability falls under CWE-77 which specifically addresses command injection flaws in software applications. The attack vector requires authentication, meaning that an attacker must first establish valid credentials to access the device's web interface before exploiting this vulnerability. This authentication requirement does not mitigate the risk significantly as it represents a privilege escalation scenario where an attacker who has already gained access to legitimate user credentials can leverage this vulnerability to execute arbitrary commands on the device.
The operational impact of this vulnerability extends beyond simple unauthorized command execution, as it provides attackers with complete control over the affected devices. An attacker with authenticated access can potentially modify network configurations, redirect traffic, install malware, or use the compromised device as a pivot point for attacks against other systems within the network. The compromised routers could serve as entry points for broader network infiltration, making this vulnerability particularly dangerous in enterprise environments where network segmentation may not be properly implemented. The affected devices are commonly deployed in residential and small business settings where network monitoring and security controls may be limited, increasing the potential for exploitation and subsequent network compromise. This vulnerability directly relates to ATT&CK technique T1059.001 which covers command and scripting interpreter, and T1068 which addresses exploit for privilege escalation.
Mitigation strategies for CVE-2021-45587 primarily focus on firmware updates and access control measures. NETGEAR has released firmware updates addressing this vulnerability in versions 3.2.16.6 and later, making firmware upgrade the primary recommended remediation. Organizations should prioritize updating all affected devices to the latest firmware versions immediately. Additionally, implementing strong access controls including regular credential rotation, limiting administrative access to only necessary personnel, and enforcing multi-factor authentication where possible can significantly reduce the risk of exploitation. Network segmentation and monitoring of network traffic can help detect suspicious activities that might indicate exploitation attempts. The vulnerability also highlights the importance of secure coding practices and input validation in network device firmware development, emphasizing the need for robust security testing and code review processes. Security professionals should also consider implementing intrusion detection systems that can identify command injection attempts within network traffic patterns. Regular security assessments and vulnerability scanning of network infrastructure should include checking for the presence of affected firmware versions to ensure comprehensive protection against this and similar vulnerabilities.