A critical stack-based buffer overflow vulnerability in multiple D-Link NAS devices allows remote attackers to execute arbitrary code or crash the system.

This vulnerability is a stack-based buffer overflow occurring in the Local_Backup_Info function within the local_backup_mgr.cgi binary. By sending a specially crafted, overly long f_idx parameter to the affected endpoint, an authenticated attacker can overwrite the function return address to achieve remote code execution.

Successful exploitation of this vulnerability poses a severe risk to organizational data integrity and availability. Because the flaw allows for arbitrary code execution, an attacker could gain full control over the NAS device, leading to unauthorized access to stored files, data exfiltration, or complete system compromise. Given the CVSS score of 8.8, this vulnerability is categorized as high severity and requires immediate attention to prevent potential service disruption or loss of sensitive information.

Immediate Action: Check the official D-Link support portal for firmware updates addressing this buffer overflow and apply them immediately to all affected devices.

Proactive Monitoring: Monitor network traffic for unusual POST requests directed at the /cgi-bin/local_backup_mgr.cgi endpoint and review system logs for signs of service crashes or unauthorized configuration changes.

Compensating Controls: Implement a Web Application Firewall (WAF) rule to inspect and block excessively long f_idx parameter values in POST requests to the identified CGI binary.

Public Exploit Available: Yes — a published proof-of-concept exists and is attributed to the researcher's write-up referenced in the CVE record.

This vulnerability represents a significant security risk due to the potential for remote code execution on storage infrastructure. Organizations should prioritize patching all D-Link NAS devices listed in the affected scope. If patching is not immediately feasible, restrict management interface access to trusted internal networks and utilize WAF filtering to mitigate the risk of exploitation until permanent updates are applied.