Ameeba Security Research

Defensive CVE and exploit intelligence

Ameeba Blog Search
TRENDING · 1 WEEK
Attack Vector
Vendor
Severity

CVE-2025-8816: Critical Buffer Overflow Vulnerability in Linksys Range Extenders

Views: 511

Overview

A critical vulnerability, identified as CVE-2025-8816, has been identified in several models of Linksys range extenders. This vulnerability is present in the setOpMode function of the /goform/setOpMode file, which can lead to a stack-based buffer overflow when manipulated via the argument ‘ethConv’. This vulnerability poses a significant threat due to its potential to compromise systems or leak data. The issue affects a wide array of Linksys devices, thereby posing a risk to a large number of users worldwide.
The vulnerability is particularly concerning as it can be exploited remotely, and the details of the exploit have been publicly disclosed. Despite being notified, the vendor has not responded to this disclosure, increasing the urgency of addressing this vulnerability.

Vulnerability Summary

CVE ID: CVE-2025-8816
Severity: Critical (8.8 CVSS 3.x Severity Score)
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: Potential system compromise or data leakage

Affected Products

Ameeba Chat Icon Share secrets securely

Ameeba is private infrastructure for communication and sensitive work built on encrypted identity instead of exposed corporate identity systems.

Passwords, credentials, confidential files, screenshots, internal discussions, sensitive AI context, and private coordination should not become exposed across ordinary communication platforms.

  • • Encrypted identity
  • • Private Spaces for organizations and teams
  • • End-to-end encrypted chat, calls, files, and notes
  • • Sensitive AI work and protected collaboration
  • • Built for information that cannot leak

Our mission is to secure human work alongside AI.

Product | Affected Versions

Linksys RE6250 | up to 20250801
Linksys RE6300 | up to 20250801
Linksys RE6350 | up to 20250801
Linksys RE6500 | up to 20250801
Linksys RE7000 | up to 20250801
Linksys RE9000 | up to 20250801

How the Exploit Works

The vulnerability lies in the setOpMode function of the /goform/setOpMode file. An attacker can manipulate the ‘ethConv’ argument to trigger a buffer overflow. Buffer overflow occurs when more data is put into a buffer than it can handle, causing it to overwrite adjacent memory areas, leading to erratic program behavior, including memory access errors, incorrect results, program termination, or a breach of system security.

Conceptual Example Code

The following is a conceptual example of how the vulnerability might be exploited using an HTTP POST request to the vulnerable endpoint:

POST /goform/setOpMode HTTP/1.1
Host: target.example.com
Content-Type: application/x-www-form-urlencoded
ethConv=AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA...

In this example, the ‘ethConv’ argument is filled with an excessively long string of ‘A’ characters, causing a buffer overflow and potentially allowing for the execution of malicious code.

Want to discuss this further? Join the Ameeba Cybersecurity Group Chat.

Disclaimer:

The information and code presented in this article are provided for educational and defensive cybersecurity purposes only. Any conceptual or pseudocode examples are simplified representations intended to raise awareness and promote secure development and system configuration practices.

Do not use this information to attempt unauthorized access or exploit vulnerabilities on systems that you do not own or have explicit permission to test.

Ameeba and its authors do not endorse or condone malicious behavior and are not responsible for misuse of the content. Always follow ethical hacking guidelines, responsible disclosure practices, and local laws.

More posts

Ameeba Chat