CVE-2018-9284 in DIR-868L
Summary
by MITRE
authentication.cgi on D-Link DIR-868L devices with Singapore StarHub firmware before v1.21SHCb03 allows remote attackers to execute arbitrary code.
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Analysis
by VulDB Data Team • 01/22/2020
The vulnerability identified as CVE-2018-9284 affects D-Link DIR-868L wireless routers running Singapore StarHub firmware versions prior to v1.21SHCb03. This critical security flaw exists within the authentication.cgi web script component of the device's web interface, creating a remote code execution opportunity that can be exploited by unauthorized attackers without requiring authentication credentials. The vulnerability represents a severe weakness in the device's access control mechanisms and demonstrates poor input validation practices that enable arbitrary code execution.
The technical root cause of this vulnerability stems from insufficient input sanitization within the authentication.cgi script, which processes user-supplied parameters without proper validation or filtering. Attackers can craft malicious payloads that exploit this weakness to inject and execute arbitrary commands on the affected device. This flaw falls under the CWE-77 vulnerability category, specifically representing a command injection vulnerability where attacker-controlled input is directly passed to system execution functions. The vulnerability allows for complete system compromise, enabling attackers to gain unauthorized access to the router's operating system and potentially the entire network infrastructure it protects.
The operational impact of this vulnerability extends far beyond simple unauthorized access, as it provides attackers with complete control over the affected router. Once exploited, adversaries can modify router configurations, redirect network traffic, install malware, or establish persistent backdoors within the network. This represents a significant threat to network security, as routers serve as critical gateways for network traffic and often contain sensitive configuration data. The vulnerability affects devices deployed in residential and small office environments where network administrators may not be actively monitoring for such exploits, making these devices particularly vulnerable to automated attacks. According to ATT&CK framework, this vulnerability maps to T1059.001 (Command and Scripting Interpreter: PowerShell) and T1566 (Phishing) as attackers can use this access to manipulate network traffic or establish further attack vectors.
Mitigation strategies for CVE-2018-9284 require immediate action from affected organizations and individuals. The primary and most effective solution involves updating the firmware to version v1.21SHCb03 or later, which includes patches addressing the input validation issues in the authentication.cgi script. Network administrators should conduct comprehensive inventory assessments to identify all affected DIR-868L devices within their networks and prioritize remediation efforts. Additional protective measures include implementing network segmentation to limit the potential impact of compromise, disabling unnecessary services on the affected devices, and monitoring network traffic for suspicious activity that might indicate exploitation attempts. Security teams should also consider deploying intrusion detection systems that can identify known exploit patterns associated with this vulnerability, and establish regular firmware update procedures to maintain device security posture. The vulnerability highlights the importance of keeping network infrastructure components updated and demonstrates the critical need for robust input validation practices in web application development to prevent similar command injection scenarios.