CVE-2025-70245: D-Link DIR-513 Buffer Overflow Vulnerability

CVE-2025-70245 Overview

A stack buffer overflow vulnerability has been identified in D-Link DIR-513 router firmware version 1.10. The vulnerability exists in the web management interface and can be triggered through the curTime parameter when making requests to the goform/formSetWizardSelectMode endpoint. This flaw allows attackers to potentially overflow the stack buffer by supplying crafted input, which could lead to denial of service or arbitrary code execution on the affected device.

Critical Impact

Attackers with network access to the router's web interface could exploit this stack buffer overflow to crash the device or potentially execute arbitrary code, compromising the integrity and availability of the network infrastructure.

Affected Products

• D-Link DIR-513 firmware version 1.10

Discovery Timeline

• 2026-03-12 - CVE-2025-70245 published to NVD
• 2026-03-12 - Last updated in NVD database

Technical Details for CVE-2025-70245

Vulnerability Analysis

This vulnerability is a stack buffer overflow that occurs in the D-Link DIR-513 router's web management interface. When processing form submissions to the goform/formSetWizardSelectMode endpoint, the firmware fails to properly validate the length of the curTime parameter before copying it into a fixed-size stack buffer. This lack of bounds checking allows an attacker to supply an oversized value that exceeds the buffer's capacity, causing adjacent memory on the stack to be overwritten.

Stack buffer overflows in embedded devices like routers are particularly dangerous because these devices often lack modern memory protection mechanisms such as ASLR (Address Space Layout Randomization) or stack canaries. This makes exploitation more reliable and increases the potential for achieving code execution.

Root Cause

The root cause of this vulnerability is improper input validation in the firmware's form handling code. The curTime parameter is accepted from user input without adequate length verification before being stored in a stack-allocated buffer. The absence of bounds checking allows data to overflow beyond the intended buffer boundaries, corrupting adjacent stack memory including potentially return addresses and saved registers.

Attack Vector

An attacker would need network access to the router's web management interface to exploit this vulnerability. The attack can be performed by sending a specially crafted HTTP POST request to the goform/formSetWizardSelectMode endpoint with an excessively long curTime parameter value. No authentication appears to be required to reach this endpoint, making remote exploitation feasible from the local network segment.

The attacker would craft a malicious HTTP request containing a curTime parameter with a payload designed to overflow the stack buffer. Depending on the specific memory layout, this could allow overwriting the return address to redirect execution flow or cause a denial of service by corrupting critical stack data.

Detection Methods for CVE-2025-70245

Indicators of Compromise

• Unusual HTTP POST requests to /goform/formSetWizardSelectMode with abnormally long curTime parameter values
• Router crashes or unexpected reboots following web interface access
• Anomalous network traffic patterns from the router suggesting compromise
• Log entries showing repeated access attempts to the wizard configuration endpoint

Detection Strategies

• Monitor web server logs for requests to goform/formSetWizardSelectMode with parameter lengths exceeding normal bounds
• Implement network-based intrusion detection rules to identify HTTP requests with oversized form parameters targeting D-Link devices
• Deploy honeypot D-Link routers to detect active scanning or exploitation attempts in your environment

Monitoring Recommendations

• Configure network monitoring to alert on unusual traffic patterns to D-Link router management interfaces
• Enable logging on the router if available and forward logs to a centralized SIEM for analysis
• Monitor for unexpected router reboots or configuration changes that may indicate successful exploitation

How to Mitigate CVE-2025-70245

Immediate Actions Required

• Restrict access to the router's web management interface to trusted IP addresses only
• Disable remote management if not required and ensure the interface is not exposed to the internet
• Implement network segmentation to limit potential attacker access to the router management interface
• Consider replacing the device with a supported model if the manufacturer does not release a firmware update

Patch Information

At the time of publication, no official patch has been confirmed for this vulnerability. Administrators should monitor the D-Link Security Bulletin page for official security advisories and firmware updates. Additional technical details are available in the GitHub CVE Report. Product information can be found on the D-Link Product Support page.

Workarounds

• Configure firewall rules to block external access to the router's web management ports (typically TCP port 80 or 443)
• Use a VPN to access the management interface rather than exposing it directly to the network
• Implement access control lists (ACLs) on upstream network devices to restrict access to the router management interface
• Disable the web management interface entirely if CLI or other management methods are available and sufficient

# Example firewall rule to restrict management access (implementation varies by firewall)
# Block external access to router management interface
iptables -A FORWARD -d <ROUTER_IP> -p tcp --dport 80 -j DROP
iptables -A FORWARD -d <ROUTER_IP> -p tcp --dport 443 -j DROP
# Allow only trusted management IP
iptables -A FORWARD -s <TRUSTED_MGMT_IP> -d <ROUTER_IP> -p tcp --dport 80 -j ACCEPT