Executive brief
The D-Link DWR-M961 is a 4G LTE router used in enterprise and remote-office deployments to provide broadband connectivity. A buffer overflow vulnerability in its web-based management interface allows attackers to execute arbitrary commands or crash the device by sending specially crafted input through configuration fields, potentially giving them complete control over network traffic and routing decisions.
Technical details
A buffer overflow vulnerability exists in the quicksetup.cgi web-management interface of the D-Link DWR-M961 router. The vulnerability is triggered by excessively long input strings supplied to the test4, ssid2, and username fields. An attacker on the network can craft a malicious payload to overflow the buffer, leading to arbitrary code execution with device privileges or causing a denial-of-service crash. The vulnerability affects hardware revision C1 running firmware version 1.1.2_C1_202602110044 and earlier; it was resolved in firmware 1.1.5_C1_202607071108. No authentication bypass is required—the web interface is typically accessible to network-connected clients.
Affected products
- D-Link DWR-M961 hardware revision C1, firmware 1.1.2_C1_202602110044 and earlier; fixed in 1.1.5_C1_202607071108
Timeline
- 2026-08-08: disclosed
- 2026-07-07: patched: firmware version 1.1.5_C1_202607071108