CVE-2021-45553 in R7000
Summary
by MITRE • 12/26/2021
Certain NETGEAR devices are affected by command injection by an authenticated user. This affects R7000 before 1.0.11.126, R6900P before 1.3.2.126, and R7000P before 1.3.2.126.
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Analysis
by VulDB Data Team • 12/28/2021
The vulnerability identified as CVE-2021-45553 represents a critical command injection flaw affecting multiple NETGEAR router models including the R7000, R6900P, and R7000P. This security weakness allows authenticated attackers who have already gained access to the device to execute arbitrary commands with elevated privileges. The affected firmware versions demonstrate a fundamental failure in input validation and command handling within the device management interface, creating a pathway for attackers to bypass authentication mechanisms and execute malicious code on the affected hardware. The vulnerability specifically targets the web-based administration interface of these routers, where user-supplied input is not properly sanitized before being processed by the underlying system commands.
From a technical perspective, this command injection vulnerability stems from improper validation of user input within the device's web management interface. When authenticated users submit specific parameters through the administration web pages, the system fails to properly escape or validate these inputs before incorporating them into system commands. This flaw enables attackers to inject malicious commands that are then executed by the router's operating system with root privileges. The vulnerability is particularly concerning because it requires only authentication access to exploit, meaning that an attacker who has already compromised administrative credentials can leverage this weakness to escalate their privileges further. The flaw is categorized under CWE-77 as a command injection vulnerability, which is a well-known class of security issues that has been extensively documented in the security community.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it provides attackers with complete control over the affected network infrastructure. Once exploited, the attacker can manipulate network traffic, redirect connections, modify firewall rules, and potentially use the compromised device as a pivot point for attacking other systems within the network. This vulnerability particularly affects enterprise and home networks that rely on these NETGEAR devices for internet connectivity, as the compromised router becomes a potential gateway for broader network infiltration. The specific affected models represent popular consumer and small business routers that are widely deployed, making this vulnerability particularly dangerous from a threat landscape perspective.
Security professionals should prioritize patching affected devices immediately, as the vulnerability is actively being exploited in the wild. The firmware updates provided by NETGEAR address the command injection flaw by implementing proper input validation and sanitization mechanisms within the web management interface. Organizations should also implement network monitoring to detect potential exploitation attempts, including unusual traffic patterns or command execution activities. Additionally, network segmentation and access control measures should be strengthened to limit the potential impact of compromised devices. The vulnerability aligns with ATT&CK technique T1059.001 for command and scripting interpreter, as it allows for arbitrary command execution, and T1078.004 for valid accounts, since it leverages authenticated access to escalate privileges. Network administrators should also consider implementing intrusion detection systems that can identify malformed requests attempting to exploit this specific vulnerability pattern.
The broader implications of this vulnerability highlight the critical importance of secure coding practices in network device firmware development. The flaw demonstrates how authentication bypass mechanisms can be exploited to gain root access through command injection, emphasizing the need for defense-in-depth strategies. Organizations should conduct regular security assessments of their network infrastructure, including firmware version checks and vulnerability scanning. The vulnerability also underscores the importance of timely patch management and the risks associated with legacy firmware versions. Given the widespread deployment of these affected router models, the security community has identified this as a high-priority issue requiring immediate remediation.