CVE-2025-70241 is a stack-based buffer overflow vulnerability identified in the D-Link DIR-513 router firmware version 1.10. The vulnerability arises from improper bounds checking of the curTime parameter passed to the goform/formSetWANType_Wizard5 endpoint, which is accessible remotely without authentication. When a specially crafted request is sent to this endpoint, it causes a stack buffer overflow, potentially overwriting the return address or other control data on the stack. Although the CVSS vector indicates no impact on confidentiality or integrity, the vulnerability results in a high impact on availability by causing the device to crash or reboot, leading to denial of service. The CVSS score of 7.5 reflects the network attack vector, low attack complexity, no privileges required, and no user interaction needed. This vulnerability is categorized under CWE-121, which involves unsafe memory operations leading to buffer overflows on the stack. No patches or mitigations have been officially released at the time of publication, and no known exploits have been observed in the wild. The vulnerability affects a widely deployed consumer-grade router, potentially exposing home and small business networks to disruption.

The primary impact of CVE-2025-70241 is on the availability of affected D-Link DIR-513 routers. Exploitation can cause the device to crash or reboot, resulting in denial of service for users relying on the router for internet connectivity. This disruption can affect home users, small businesses, and potentially branch offices that use this router model. While the vulnerability does not directly compromise confidentiality or integrity, the loss of network availability can hinder business operations, remote work, and access to critical online services. Additionally, repeated exploitation attempts could lead to persistent network outages or require physical intervention to restore service. Given the router’s role as a network gateway, its unavailability can also impact connected IoT devices and security monitoring systems dependent on continuous network access.

1. Network Segmentation: Isolate the affected D-Link DIR-513 routers from critical network segments to limit the impact of potential denial of service. 2. Access Control: Restrict remote management access to the router’s web interface, especially the goform endpoints, by limiting access to trusted IP addresses or disabling remote administration if not required. 3. Monitoring and Detection: Implement network monitoring to detect unusual traffic patterns targeting the goform/formSetWANType_Wizard5 endpoint or repeated malformed requests that could indicate exploitation attempts. 4. Firmware Updates: Regularly check for official firmware updates or security advisories from D-Link addressing this vulnerability and apply patches promptly once available. 5. Device Replacement: Consider replacing affected routers with models that have received security updates or have a better security track record if patches are not forthcoming. 6. Incident Response Preparedness: Prepare for potential denial of service incidents by having backup connectivity options and procedures to quickly restore network access if the router becomes unresponsive.