Listen to this Post
The CVE-2025-70218 details a critical stack-based buffer overflow vulnerability in the D-Link DIR-513 router, specifically in firmware version 1.10 . The issue resides within the Boa web server component that handles HTTP POST requests sent to the `/goform/formAdvFirewall` endpoint . When processing these requests, the device fails to properly validate the length of input provided through specific parameters, such as curTime, before copying it into a fixed-size stack buffer using unsafe functions like `sprintf` . An unauthenticated attacker on the same network can send a specially crafted POST request with an overly long string. Because there are no bounds checks, this string overwrites adjacent memory on the stack, corrupting the program’s return address and control flow . This memory corruption allows the attacker to inject and execute arbitrary malicious code, effectively taking full control of the router, which can lead to data theft, network intrusion, or denial of service .
dailycve form:
Platform: D-Link DIR-513
Version: 1.10
Vulnerability : Stack Buffer Overflow
Severity: Critical
date: 2026-03-04
Prediction: No Patch (EOL)
What Undercode Say:
Analytics
The vulnerability stems from insecure coding practices in the Boa web server, specifically the use of `sprintf` without length limitations. The `curTime` parameter in the POST request to `/goform/formAdvFirewall` is copied into a stack buffer (v68) without checking its size, leading to memory corruption . The product is End-of-Life (EOL), meaning the vendor will not release a security patch, leaving all devices running version 1.10 permanently vulnerable .
How Exploit:
The following is a conceptual example of how an attacker might trigger the overflow. This is for educational purposes only.
Identify the target router TARGET_IP="192.168.0.1" Craft a malicious payload The 'A'5000 is a long string designed to overflow the buffer. The exact offset and shellcode would need to be determined via reverse engineering. PAYLOAD="A"'5000 Send the malicious POST request using curl curl -X POST http://$TARGET_IP/goform/formAdvFirewall \ -d "curTime=$PAYLOAD"
Protection from this CVE
Since no official patch exists, the only effective mitigation is to isolate or replace the affected hardware.
Option 1: Isolate the device (Example using iptables on a Linux gateway) Block all incoming traffic from the WAN side to the router's management interface. (Assuming eth0 is WAN and router IP is 192.168.0.1 on LAN side, this prevents external attacks) sudo iptables -A FORWARD -d 192.168.0.1 -p tcp --dport 80 -j DROP sudo iptables -A FORWARD -d 192.168.0.1 -p tcp --dport 443 -j DROP Option 2: Create a custom firewall rule on the router itself (if accessible) to drop malformed requests. This is a conceptual iptables rule to block excessive packet sizes on port 80. (Requires BusyBox/iptables on the router) iptables -A INPUT -p tcp --dport 80 -m length --length 1500:65535 -j DROP
Impact
Successful exploitation leads to Remote Code Execution (RCE) with root privileges on the device. This compromises the confidentiality, integrity, and availability of the router. Attackers can use the compromised router as a pivot point to attack other devices on the internal network, intercept or modify traffic, or add the device to a botnet for large-scale attacks .
🎯Let’s Practice Exploiting & Learn Patching For Free:
Sources:
Reported By: nvd.nist.gov
Extra Source Hub:
Undercode
🔐JOIN OUR CYBER WORLD [ CVE News • HackMonitor • UndercodeNews ]
📢 Follow DailyCVE & Stay Tuned:
𝕏 formerly Twitter 🐦 | @ Threads | 🔗 Linkedin
D-Link DIR-513, Stack Buffer Overflow, CVE-2025-70221 (Critical)