CVE-2026-7288: D-Link DIR-825M Buffer Overflow Vulnerability

CVE-2026-7288 Overview

CVE-2026-7288 is a buffer overflow vulnerability in the D-Link DIR-825M router running firmware version 1.1.12. The flaw exists in the sub_4151FC function within the /boafrm/formVpnConfigSetup endpoint of the device's web management interface. Attackers can trigger the overflow by manipulating the submit-url parameter. The vulnerability is remotely exploitable over the network and requires low-level privileges. Public disclosure of the exploit details has occurred, increasing the risk of weaponization against exposed devices. The issue is classified under [CWE-119] (Improper Restriction of Operations within the Bounds of a Memory Buffer).

Critical Impact
Remote attackers with low privileges can trigger memory corruption in the router's HTTP daemon, potentially leading to denial of service or arbitrary code execution on affected D-Link DIR-825M devices.

Affected Products

D-Link DIR-825M router (hardware revision)
D-Link DIR-825M firmware version 1.1.12
Web management component /boafrm/formVpnConfigSetup (function sub_4151FC)

Discovery Timeline

2026-04-28 - CVE-2026-7288 published to NVD
2026-04-30 - Last updated in NVD database

Technical Details for CVE-2026-7288

Vulnerability Analysis

The vulnerability resides in the sub_4151FC function of the boa web server binary that handles VPN configuration requests on the DIR-825M. When a client submits a request to /boafrm/formVpnConfigSetup, the handler reads the submit-url argument from the HTTP request without enforcing length validation. The data is copied into a fixed-size stack or heap buffer, enabling memory corruption when the attacker-supplied value exceeds the allocated capacity. Because the boa daemon typically runs with elevated privileges on embedded D-Link devices, successful corruption can lead to control-flow hijacking. The attack vector is network-based and does not require user interaction, though authenticated low-privilege access is needed.

Root Cause

The root cause is improper restriction of operations within the bounds of a memory buffer [CWE-119]. The submit-url argument handler lacks bounds checking before the copy operation. Embedded routers running the boa HTTP server frequently use unsafe string functions such as strcpy or sprintf without validating input length, which produces classic stack-based overflows on MIPS or ARM SoCs.

Attack Vector

An authenticated attacker sends a crafted HTTP POST request to /boafrm/formVpnConfigSetup containing an oversized submit-url parameter. The malformed request causes the sub_4151FC function to write past the destination buffer, corrupting adjacent memory. Depending on heap and stack layout, the attacker can crash the service or overwrite a saved return address to redirect execution. Technical analysis details are available in the GitHub CVE Issue Discussion and the VulDB Vulnerability #359946 entry.

No verified proof-of-concept code is available in trusted public repositories at this time. The vulnerability mechanism follows the standard pattern for boa-based router overflows: an unbounded copy of an HTTP form parameter into a fixed-size buffer within the request handler.

Detection Methods for CVE-2026-7288

Indicators of Compromise

HTTP requests to /boafrm/formVpnConfigSetup containing abnormally long submit-url parameter values, especially exceeding several hundred bytes.
Unexpected restarts or crashes of the boa HTTP daemon on DIR-825M devices, visible in syslog as service respawn events.
Outbound connections from the router to unknown external hosts following VPN configuration page activity.

Detection Strategies

Inspect web traffic destined for router management interfaces and flag POST requests with submit-url payloads exceeding expected URL length limits.
Deploy network intrusion detection signatures that match oversized form parameters submitted to /boafrm/ endpoints on D-Link devices.
Correlate authentication events against the router admin panel with subsequent crashes of the embedded HTTP service.

Monitoring Recommendations

Forward router syslog output to a centralized logging platform and alert on repeated boa process termination events.
Monitor for unauthorized changes to VPN configuration on edge routers using configuration drift tooling.
Track external scans probing for /boafrm/formVpnConfigSetup across perimeter telemetry to identify reconnaissance activity.

How to Mitigate CVE-2026-7288

Immediate Actions Required

Restrict access to the DIR-825M web management interface to trusted internal hosts and disable remote WAN-side administration.
Rotate administrator credentials on affected devices to reduce the chance that low-privilege accounts can reach the vulnerable endpoint.
Inventory all DIR-825M devices running firmware 1.1.12 and isolate those exposed to untrusted networks.

Patch Information

No vendor patch has been published in the available references at the time of NVD publication. The DIR-825M is an older consumer router model and may have reached end-of-support status. Administrators should consult the D-Link Security Resources page for any subsequent firmware advisories and consider replacing affected hardware with a currently supported model if no fix becomes available.

Workarounds

Disable the VPN configuration feature on the DIR-825M if it is not required for production use.
Place the router behind an upstream firewall and block inbound HTTP/HTTPS access to the management interface from untrusted segments.
Apply network segmentation so that only designated administrative workstations can reach the router's management VLAN.
Replace end-of-life DIR-825M units with currently supported router models that receive active firmware maintenance.

bash

# Example: block external access to the router admin interface using iptables on an upstream gateway
iptables -A FORWARD -d 192.0.2.1 -p tcp --dport 80 -j DROP
iptables -A FORWARD -d 192.0.2.1 -p tcp --dport 443 -j DROP

# Allow only a designated management host
iptables -I FORWARD -s 10.10.10.25 -d 192.0.2.1 -p tcp --dport 80 -j ACCEPT