CVE-2021-38521 in R6400
Summary
by MITRE • 08/11/2021
Certain NETGEAR devices are affected by command injection by an authenticated user. This affects R6400 before 1.0.1.50, R7900P before 1.4.1.50, R8000P before 1.4.1.50, RAX75 before 1.0.1.62, and RAX80 before 1.0.1.62.
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Analysis
by VulDB Data Team • 08/16/2021
This vulnerability represents a critical command injection flaw affecting multiple NETGEAR router models that allows authenticated users to execute arbitrary commands on the affected devices. The vulnerability stems from insufficient input validation and sanitization within the web interface authentication mechanisms, creating a pathway for privilege escalation attacks. The affected models include R6400, R7900P, R8000P, RAX75, and RAX80 routers, with specific firmware versions indicating the scope of impacted devices. The vulnerability is classified under CWE-77 as command injection, which is a well-documented weakness in web applications and network devices that can lead to complete system compromise.
The technical exploitation of this vulnerability requires an attacker to first establish authentication credentials, either through legitimate access or credential compromise, before executing malicious commands that can manipulate the device's underlying operating system. The flaw allows for arbitrary command execution within the context of the device's privileged user account, potentially enabling attackers to modify network configurations, install malware, or extract sensitive data from the affected network infrastructure. This type of vulnerability falls under the ATT&CK technique T1059.001 for command and scripting interpreter, specifically targeting the command shell component of network devices.
The operational impact of this vulnerability extends beyond individual device compromise to potentially affect entire network infrastructures, as routers serve as critical gateways for network traffic. An authenticated attacker could leverage this vulnerability to redirect network traffic, establish backdoors, or disable network services entirely. The affected firmware versions indicate that the vulnerability has persisted across multiple generations of devices, suggesting a systemic issue in the development and testing processes for these network appliances. Organizations relying on these devices for network security may find their firewalls, NAT configurations, and access controls compromised, potentially exposing their internal networks to further attacks.
Mitigation strategies should include immediate firmware updates to the latest available versions that address the command injection vulnerability, along with network segmentation to limit the potential impact of device compromise. Network administrators should also implement monitoring solutions to detect unusual command execution patterns and establish strict access controls to prevent unauthorized authentication. The vulnerability demonstrates the importance of secure coding practices and proper input validation in network device firmware, as well as the critical need for regular security assessments and vulnerability management processes. Organizations should also consider implementing network access controls and intrusion detection systems to identify potential exploitation attempts and maintain comprehensive network monitoring capabilities to detect unauthorized command execution activities.