CVE-2025-70233: D-Link DIR-513 Buffer Overflow Flaw

CVE-2025-70233 Overview

A stack buffer overflow vulnerability has been identified in D-Link DIR-513 v1.10 routers. The vulnerability exists in the goform/formSetEnableWizard endpoint and can be triggered through the curTime parameter. Stack buffer overflow vulnerabilities in embedded devices like routers are particularly concerning as they can potentially allow attackers to execute arbitrary code, crash the device, or gain unauthorized access to the network infrastructure.

Critical Impact

Successful exploitation of this stack buffer overflow vulnerability could allow attackers to execute arbitrary code on the affected D-Link router, potentially compromising the entire network segment behind the device.

Affected Products

• D-Link DIR-513 v1.10

Discovery Timeline

• 2026-03-05 - CVE CVE-2025-70233 published to NVD
• 2026-03-05 - Last updated in NVD database

Technical Details for CVE-2025-70233

Vulnerability Analysis

This vulnerability is classified as a stack buffer overflow, a type of memory corruption flaw that occurs when a program writes data beyond the boundaries of a fixed-length buffer allocated on the stack. In the case of CVE-2025-70233, the vulnerable code resides in the web management interface of the D-Link DIR-513 router, specifically within the formSetEnableWizard form handler.

When processing the curTime parameter, the affected firmware fails to properly validate the length of user-supplied input before copying it into a stack-allocated buffer. This lack of bounds checking allows an attacker to supply an overly long string that overwrites adjacent stack memory, including potentially critical values such as the return address.

Root Cause

The root cause of this vulnerability is improper input validation in the router's web interface firmware. The goform/formSetEnableWizard handler accepts the curTime parameter without performing adequate length checks before storing the value in a fixed-size stack buffer. This is a classic example of unsafe string handling commonly found in embedded device firmware, where memory-safe programming practices may not be consistently applied.

Attack Vector

The attack vector for this vulnerability involves sending a crafted HTTP request to the router's web management interface. An attacker with network access to the router's administrative interface could exploit this vulnerability by submitting a malicious request to the /goform/formSetEnableWizard endpoint with an oversized curTime parameter value.

The exploitation would typically involve:

1. Accessing the router's web management interface
2. Sending a POST request to /goform/formSetEnableWizard with an excessively long curTime parameter
3. The oversized input overflows the stack buffer, potentially overwriting the return address
4. If successfully exploited, this could lead to denial of service or arbitrary code execution

For detailed technical information regarding the vulnerability mechanics, refer to the GitHub CVE Report.

Detection Methods for CVE-2025-70233

Indicators of Compromise

• Unusual HTTP POST requests to /goform/formSetEnableWizard containing abnormally long curTime parameter values
• Unexpected router reboots or crashes that may indicate exploitation attempts
• Anomalous network traffic patterns originating from or targeting the router's web management interface
• Log entries showing repeated access attempts to the formSetEnableWizard endpoint

Detection Strategies

• Implement network intrusion detection rules to identify HTTP requests with oversized parameters targeting D-Link router endpoints
• Monitor for HTTP POST requests to /goform/formSetEnableWizard with curTime parameter lengths exceeding normal operational values
• Deploy web application firewall rules to block requests containing excessively long parameter values
• Enable verbose logging on network perimeter devices to capture suspicious traffic patterns

Monitoring Recommendations

• Regularly review router access logs for unauthorized access attempts or anomalous patterns
• Implement network segmentation to isolate IoT and network infrastructure devices
• Set up alerts for repeated failed authentication attempts or unusual administrative interface access
• Monitor for unexpected changes to router configuration or firmware

How to Mitigate CVE-2025-70233

Immediate Actions Required

• Restrict access to the router's web management interface to trusted IP addresses only
• Disable remote management if not required for operations
• Place the router behind a properly configured firewall that filters incoming traffic
• Consider network segmentation to limit exposure of vulnerable devices

Patch Information

Consult the D-Link Security Bulletin for official patch availability and firmware updates. For product-specific information and support, visit the D-Link Product Information page. As of the last update to this CVE, users should verify if D-Link has released a patched firmware version for the DIR-513.

Workarounds

• Disable the web management interface and use alternative management methods if available
• Implement strict access control lists (ACLs) to limit management interface access to specific trusted hosts
• Use a VPN to access the router's management interface rather than exposing it directly to the network
• If the router is end-of-life, consider replacing it with a supported model that receives security updates

# Example: Restrict management interface access via iptables (if accessible via SSH)
# Block external access to web management port
iptables -A INPUT -p tcp --dport 80 -s 192.168.1.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP