CVE-2018-21104 in R7800
Summary
by MITRE
NETGEAR R7800 devices before 1.0.2.60 are affected by command injection by an authenticated user.
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Analysis
by VulDB Data Team • 06/02/2024
The vulnerability identified as CVE-2018-21104 affects NETGEAR R7800 wireless routers running firmware versions prior to 1.0.2.60, representing a critical command injection flaw that allows authenticated attackers to execute arbitrary commands on the affected devices. This vulnerability stems from insufficient input validation and sanitization within the router's web interface administration functionality, specifically in how the device processes user-supplied parameters. The issue manifests when an authenticated user submits malicious input through specific web forms or API endpoints, which are then improperly handled and executed as system commands without adequate sanitization measures. The vulnerability is classified under CWE-77 as a command injection weakness, where attacker-controlled data is interpreted and executed as shell commands by the underlying operating system. This flaw directly violates the principle of least privilege and demonstrates a critical failure in input validation mechanisms that should prevent unauthorized command execution.
The operational impact of this vulnerability extends beyond simple privilege escalation as it provides attackers with complete control over the affected router's functionality. Once exploited, an authenticated attacker can execute arbitrary system commands with the privileges of the web server process, potentially leading to full system compromise, data exfiltration, or the ability to modify network configurations. The vulnerability affects the router's administrative interface, which typically requires valid credentials to access, making it a post-authentication issue that can be exploited by insiders or attackers who have obtained valid user credentials. This command injection vulnerability can be leveraged to install malicious software, redirect network traffic, modify firewall rules, or even create backdoors for persistent access to the network. The affected devices operate on embedded operating systems that are particularly vulnerable to such injection attacks due to their limited security hardening and the complexity of managing multiple input vectors in network device interfaces.
Mitigation strategies for CVE-2018-21104 primarily focus on firmware updates and network segmentation measures to limit the potential impact of exploitation. Users should immediately upgrade to firmware version 1.0.2.60 or later, which includes proper input validation and sanitization mechanisms that prevent command injection attacks. Network administrators should also implement strict access controls and monitor for unusual administrative activities that might indicate exploitation attempts. The vulnerability aligns with ATT&CK technique T1059.001 for command and scripting interpreter, specifically shell scripting, and represents a classic example of how insufficient input validation can lead to privilege escalation and system compromise. Additional protective measures include implementing network access control lists, disabling unnecessary administrative services, and conducting regular security assessments of network infrastructure devices. Organizations should also consider deploying intrusion detection systems that can identify suspicious command execution patterns and establish incident response procedures specifically tailored to network device compromises. The vulnerability underscores the importance of maintaining up-to-date firmware and the critical need for proper input validation in embedded systems, particularly those handling administrative interfaces with elevated privileges.