CVE-2016-6277 in R6250
Summary
by MITRE
NETGEAR R6250 before 1.0.4.6.Beta, R6400 before 1.0.1.18.Beta, R6700 before 1.0.1.14.Beta, R6900, R7000 before 1.0.7.6.Beta, R7100LG before 1.0.0.28.Beta, R7300DST before 1.0.0.46.Beta, R7900 before 1.0.1.8.Beta, R8000 before 1.0.3.26.Beta, D6220, D6400, D7000, and possibly other routers allow remote attackers to execute arbitrary commands via shell metacharacters in the path info to cgi-bin/.
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Analysis
by VulDB Data Team • 02/04/2025
This vulnerability represents a critical remote command execution flaw affecting multiple NETGEAR router models including R6250, R6400, R6700, R6900, R7000, R7100LG, R7300DST, R7900, R8000, and several D-series devices. The vulnerability exists in the handling of path information within the cgi-bin/ directory of these network appliances, specifically when shell metacharacters are present in the request path. This flaw falls under the CWE-77 category of "Improper Neutralization of Special Elements used in a Command ('Command Injection')", which is a well-established vulnerability pattern in cybersecurity. The issue allows remote attackers to inject and execute arbitrary shell commands on the affected devices without requiring authentication, making it particularly dangerous for network infrastructure.
The technical implementation of this vulnerability stems from insufficient input validation and sanitization within the router's web interface handling mechanism. When a malicious actor sends a crafted HTTP request containing shell metacharacters such as semicolons, ampersands, or backticks within the path information parameter, the router's web server fails to properly sanitize this input before processing it in a shell context. This occurs specifically in the cgi-bin/ directory where the router's web interface executes system commands through the shell. The vulnerability is classified as a command injection attack under the MITRE ATT&CK framework, specifically mapping to technique T1059.001 for Command and Scripting Interpreter. The affected devices are particularly vulnerable because they process user-supplied path information without proper sanitization, creating an attack surface that can be exploited from any network location.
The operational impact of this vulnerability is severe and far-reaching for network administrators and end users. Successful exploitation allows attackers to gain complete control over the affected router, enabling them to modify network configurations, redirect traffic, install malware, or establish persistent backdoors within the network infrastructure. The vulnerability affects not just individual devices but entire network segments since routers serve as central points of control for network traffic. Network administrators may lose visibility into their network operations, as attackers can modify firewall rules, disable security features, or create unauthorized access points. The lack of authentication requirements means that any remote attacker can exploit this vulnerability, potentially leading to widespread network compromise and data exfiltration across multiple devices. This vulnerability directly impacts the CIA triad by compromising confidentiality, integrity, and availability of network resources.
Mitigation strategies for this vulnerability require immediate attention from network administrators. The most effective immediate solution is to upgrade all affected NETGEAR router models to their patched firmware versions, specifically targeting the firmware versions mentioned in the CVE description where patches are available. Network segmentation and firewall rules should be implemented to restrict access to the router's web interface from untrusted networks, particularly blocking access to the cgi-bin/ directory. Network administrators should also implement intrusion detection systems to monitor for suspicious HTTP requests containing shell metacharacters. Regular firmware updates and security assessments should be conducted to prevent similar vulnerabilities from being introduced in the future. Organizations should also consider implementing network access control measures that limit direct internet access to network infrastructure devices. Additionally, security teams should monitor for any unauthorized changes to router configurations and establish baseline configurations that can be quickly restored in case of compromise. The vulnerability demonstrates the critical importance of input validation in web applications and the need for robust security practices in embedded network devices that are often overlooked in traditional security assessments.