CVE-2025-70232 Overview
A stack buffer overflow vulnerability has been identified in D-Link DIR-513 v1.10 wireless routers. The vulnerability exists in the goform/formSetMACFilter endpoint, which fails to properly validate the length of the curTime parameter before copying it to a stack-based buffer. This memory corruption flaw allows attackers to overwrite adjacent stack memory, potentially leading to arbitrary code execution on the affected device.
Critical Impact
Successful exploitation of this stack buffer overflow could allow remote attackers to execute arbitrary code on the affected D-Link router, potentially gaining full control over the device and compromising network security.
Affected Products
- D-Link DIR-513 v1.10
Discovery Timeline
- March 5, 2026 - CVE CVE-2025-70232 published to NVD
- March 5, 2026 - Last updated in NVD database
Technical Details for CVE-2025-70232
Vulnerability Analysis
This stack buffer overflow vulnerability affects the MAC filter configuration functionality in D-Link DIR-513 routers running firmware version 1.10. The vulnerable endpoint goform/formSetMACFilter processes HTTP form submissions for configuring MAC address filtering on the device.
The core issue lies in the improper handling of the curTime parameter. When a user or attacker submits data to this endpoint, the application copies the value of curTime into a fixed-size stack buffer without performing adequate bounds checking. If an attacker provides an excessively long string for this parameter, the data overflows beyond the allocated buffer space on the stack.
Stack buffer overflows are particularly dangerous in embedded systems like routers because they often lack modern exploit mitigation techniques such as Address Space Layout Randomization (ASLR), stack canaries, or non-executable stack protections. This makes exploitation more reliable and increases the risk of successful code execution attacks.
Root Cause
The root cause of this vulnerability is insufficient input validation and the use of unsafe memory copy operations when handling the curTime parameter in the formSetMACFilter form handler. The application allocates a fixed-size buffer on the stack to store the parameter value but does not verify that the input length does not exceed this buffer size before performing the copy operation. This classic buffer overflow pattern allows attackers to corrupt stack memory, overwrite return addresses, and potentially hijack program execution flow.
Attack Vector
An attacker can exploit this vulnerability by sending a specially crafted HTTP POST request to the goform/formSetMACFilter endpoint on the affected D-Link DIR-513 router. The attack involves supplying an oversized curTime parameter value designed to overflow the stack buffer.
If the attacker has network access to the router's web management interface, they can craft a malicious request containing a payload in the curTime parameter. This payload would include padding data to fill the buffer, followed by crafted values to overwrite the saved return address on the stack. When the vulnerable function returns, execution would jump to attacker-controlled code, potentially granting full control over the router.
The attack could be launched directly if the router's web interface is accessible, or potentially via Cross-Site Request Forgery (CSRF) if an authenticated administrator visits a malicious website.
Detection Methods for CVE-2025-70232
Indicators of Compromise
- Unusual HTTP POST requests to /goform/formSetMACFilter containing abnormally long curTime parameter values
- Router instability, crashes, or unexpected reboots that may indicate exploitation attempts
- Unauthorized changes to router configuration or MAC filter settings
- Unexpected outbound network connections from the router device
Detection Strategies
- Monitor network traffic for HTTP requests to D-Link management interfaces containing oversized form parameters
- Implement intrusion detection rules to flag requests to goform/formSetMACFilter with curTime values exceeding normal length thresholds
- Deploy network segmentation to limit access to router management interfaces
Monitoring Recommendations
- Enable logging on network firewalls to capture traffic destined for router management ports (typically port 80/443)
- Review router access logs for unusual access patterns or repeated requests to form submission endpoints
- Consider deploying network monitoring solutions to detect anomalous traffic patterns targeting embedded devices
How to Mitigate CVE-2025-70232
Immediate Actions Required
- Restrict access to the D-Link DIR-513 web management interface to trusted networks only
- Disable remote management if not required
- Place the router behind a firewall that blocks external access to the management interface
- Consider replacing the affected device with a currently supported model
Patch Information
Check the D-Link Security Bulletin for official security advisories and firmware updates. Additionally, consult the D-Link Product Support Page for the latest firmware availability.
For technical details about this vulnerability, refer to the GitHub CVE Report Repository.
Workarounds
- Implement network access controls (ACLs) to restrict which IP addresses can access the router's web interface
- Use a VPN to access the management interface rather than exposing it directly
- Disable the HTTP/HTTPS management interface if CLI or other management methods are available
- Monitor for and apply firmware updates as they become available from D-Link
# Example: Restrict management interface access using upstream firewall rules
# Block external access to router management (adjust IP as needed)
iptables -A FORWARD -d 192.168.1.1 -p tcp --dport 80 -j DROP
iptables -A FORWARD -d 192.168.1.1 -p tcp --dport 443 -j DROP
# Allow only trusted admin subnet
iptables -I FORWARD -s 192.168.1.0/24 -d 192.168.1.1 -p tcp --dport 80 -j ACCEPT
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
