CVE-2021-45580 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-2021-45580 represents a critical command injection flaw affecting multiple NETGEAR router models including RBK752, RBR750, RBS750, RBK852, RBR850, and RBS850. This vulnerability exists within the web-based management interface of these devices and allows authenticated attackers to execute arbitrary commands on the affected systems. The flaw stems from insufficient input validation and sanitization within the device's command processing mechanisms, creating an avenue for malicious actors to inject and execute system commands through crafted input parameters. The vulnerability is particularly concerning because it requires only authentication credentials to exploit, meaning that any individual with access to the device's management interface can potentially gain full system control. This issue falls under CWE-77 which specifically addresses command injection vulnerabilities, and aligns with ATT&CK technique T1059.001 for command and scripting interpreter, as well as T1068 for exploit for privilege escalation. The affected firmware versions prior to 3.2.16.6 indicate that this was a persistent flaw that had not been adequately addressed in the device's software lifecycle.
The technical implementation of this vulnerability occurs within the web interface's handling of user-supplied input, where commands are directly passed to system execution functions without proper sanitization or validation. Attackers can exploit this by crafting malicious input that includes shell commands, which are then executed with the privileges of the web interface process. This creates a pathway for attackers to gain unauthorized access to the device's underlying operating system, potentially allowing them to modify device configurations, extract sensitive information, install malware, or use the device as a pivot point for attacks on other systems within the network. The authenticated nature of the exploit means that the attack vector is significantly reduced compared to unauthenticated vulnerabilities, as attackers need only obtain legitimate user credentials rather than performing complex reconnaissance or exploitation techniques.
The operational impact of this vulnerability extends beyond simple unauthorized access, as it provides attackers with complete control over the affected network devices. Once exploited, attackers can manipulate network traffic, modify firewall rules, change routing configurations, and potentially use the compromised devices as entry points for broader network infiltration. The affected devices are typically deployed in residential and small office environments where they serve as primary network gateways, making them attractive targets for cybercriminals seeking persistent access to larger networks. This vulnerability can be exploited to establish backdoors, enable persistent surveillance, or facilitate data exfiltration from the network. Organizations using these devices should be particularly concerned about potential supply chain attacks or insider threats, as the compromised devices could serve as long-term footholds within their network infrastructure. The impact is further amplified by the fact that these devices often lack robust logging capabilities, making detection of exploitation attempts more difficult.
Mitigation strategies for CVE-2021-45580 primarily focus on firmware updates and access control measures. NETGEAR has released firmware version 3.2.16.6 and later to address this vulnerability, which should be deployed immediately across all affected devices. Organizations should also implement strict access controls including strong authentication mechanisms, regular credential rotation, and monitoring of administrative access logs. Network segmentation and the implementation of intrusion detection systems can help detect potential exploitation attempts. Additionally, administrators should consider disabling unnecessary web management interfaces and implementing multi-factor authentication where possible. The vulnerability highlights the importance of maintaining up-to-date firmware and conducting regular security assessments of network infrastructure. Security teams should also implement network monitoring to detect unusual command execution patterns and ensure that all network devices are properly configured with the latest security patches. This vulnerability serves as a reminder of the critical need for robust software security practices in embedded systems and the importance of proper input validation in web applications.