CVE-2016-4815 in WZR-600DHP3
Summary
by MITRE
Directory traversal vulnerability on BUFFALO WZR-600DHP3 devices with firmware 2.16 and earlier and WZR-S600DHP devices with firmware 2.16 and earlier allows remote attackers to read arbitrary files via unspecified vectors.
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Analysis
by VulDB Data Team • 01/30/2019
The CVE-2016-4815 vulnerability represents a critical directory traversal flaw affecting BUFFALO WZR-600DHP3 and WZR-S600DHP wireless routers running firmware versions 2.16 and earlier. This vulnerability falls under the Common Weakness Enumeration category CWE-22, which specifically addresses improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal attacks. The flaw enables remote attackers to access arbitrary files on the affected devices through unspecified vectors that exploit insufficient input validation mechanisms within the router's web interface.
The technical implementation of this vulnerability stems from inadequate sanitization of user-supplied input parameters in the web application layer of the router's firmware. Attackers can manipulate file path parameters to navigate outside the intended directory structure and access sensitive system files, configuration data, and potentially credentials stored on the device. The unspecified vectors suggest that multiple entry points within the device's web interface could be exploited, making the vulnerability particularly dangerous as it may be accessible through various attack surfaces including configuration pages, diagnostic tools, or file management functions.
From an operational impact perspective, this vulnerability poses significant risks to network security and device integrity. Remote attackers who successfully exploit this vulnerability can gain unauthorized access to confidential information stored on the router, including but not limited to administrative credentials, network configuration details, and potentially sensitive data from connected systems. The attack surface extends beyond the individual device to encompass the entire network infrastructure, as router credentials often provide access to internal network resources and can serve as a foothold for further lateral movement within the network. The vulnerability's remote exploitability means that attackers do not require physical access to the device or network presence to launch attacks, making it particularly concerning for enterprise and home network deployments.
The mitigation strategies for CVE-2016-4815 should prioritize immediate firmware updates from BUFFALO to address the directory traversal vulnerability. Organizations should also implement network segmentation and access controls to limit exposure, particularly for critical network infrastructure devices. Network monitoring solutions should be configured to detect unusual file access patterns or attempts to access system directories. The vulnerability demonstrates the importance of secure coding practices and input validation in embedded systems, aligning with ATT&CK technique T1213 for data from information repositories and T1078 for valid accounts, as attackers may use compromised router credentials to establish persistence and access network resources. Additionally, implementing web application firewalls and network access control policies can provide additional layers of defense against exploitation attempts.