D-Link DIR-825M Remote Buffer Overflow Vulnerability

A buffer overflow vulnerability exists in D-Link DIR-825M router version 1.1.12. The vulnerability is located within the sub_414BA8 function of the /boafrm/formWanConfigSetup file. An attacker can exploit this flaw by manipulating the submit-url argument, leading to arbitrary code execution on the device. This vulnerability is remotely exploitable, and a proof-of-concept exploit is publicly available, increasing the risk of widespread attacks. Exploitation does not require authentication by default, and could allow an attacker to gain complete control over the device. This poses a significant threat to home and small business networks relying on this router model.

Attack Chain

1. The attacker identifies a vulnerable D-Link DIR-825M router running firmware version 1.1.12.
2. The attacker crafts a malicious HTTP POST request targeting the /boafrm/formWanConfigSetup endpoint.
3. The attacker includes the submit-url argument in the POST request, injecting a buffer overflow payload.
4. The crafted payload overflows the buffer in the sub_414BA8 function during the processing of the submit-url argument.
5. The buffer overflow overwrites critical memory regions, including the return address.
6. When the sub_414BA8 function returns, control is redirected to the attacker-controlled address.
7. The attacker’s payload executes arbitrary code, potentially downloading and executing a secondary payload.
8. The attacker gains remote shell access to the router.

Impact

Successful exploitation of this buffer overflow vulnerability allows a remote attacker to execute arbitrary code on the D-Link DIR-825M router. This can lead to complete compromise of the device, allowing the attacker to eavesdrop on network traffic, modify router settings, or use the router as a botnet node for further malicious activities. Given the widespread use of D-Link routers in home and small business networks, a successful attack could compromise a large number of devices and networks.

Recommendation

• Apply available firmware updates from D-Link to patch CVE-2026-7289.
• Deploy the following Sigma rule to detect suspicious POST requests to /boafrm/formWanConfigSetup with overly long submit-url parameters.
• Monitor web server logs for suspicious activity related to the /boafrm/formWanConfigSetup endpoint.