CVE-2025-8816 in RE6250
Summary
by MITRE • 08/10/2025
A vulnerability was determined in Linksys RE6250, RE6300, RE6350, RE6500, RE7000 and RE9000 up to 20250801. Affected is the function setOpMode of the file /goform/setOpMode. The manipulation of the argument ethConv leads to stack-based buffer overflow. It is possible to launch the attack remotely. The exploit has been disclosed to the public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.
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Analysis
by VulDB Data Team • 08/13/2025
This vulnerability exists in multiple Linksys router models including RE6250, RE6300, RE6350, RE6500, RE7000, and RE9000 firmware versions up to 20250801. The flaw is located in the setOpMode function within the /goform/setOpMode file which handles operational mode configuration for the device. The specific technical issue occurs when processing the ethConv argument parameter, creating a stack-based buffer overflow condition that can be exploited through remote network access. This represents a critical security weakness that allows attackers to execute arbitrary code on affected devices without requiring physical access or authentication credentials.
The vulnerability stems from improper input validation within the web-based management interface of these routers. When the ethConv parameter is manipulated during the setOpMode function execution, the system fails to properly bounds-check the input data before copying it into a fixed-size stack buffer. This classic buffer overflow condition occurs because the application does not verify that the input data length exceeds the allocated buffer space, allowing an attacker to overwrite adjacent stack memory locations. The attack vector is particularly dangerous as it can be executed remotely over the network, making it accessible to any attacker who can reach the device's web management interface.
The operational impact of this vulnerability is severe and multifaceted. Successful exploitation could enable remote code execution, allowing attackers to gain full administrative control over the affected routers. This would provide unauthorized access to network traffic, the ability to modify router configurations, and potential pivoting points for attacks on internal network resources. The vulnerability affects not just individual devices but entire networks that rely on these routers for connectivity, as compromised devices can serve as entry points for broader network infiltration. Additionally, the disclosed exploit means that threat actors can immediately leverage this weakness without requiring advanced technical skills or custom development.
From a cybersecurity perspective, this vulnerability aligns with CWE-121 Stack-based Buffer Overflow, which is categorized under the broader class of buffer overflow weaknesses that have been consistently identified as critical threats in the software security landscape. The ATT&CK framework would classify this as a technique involving remote code execution through web application vulnerabilities, potentially leading to privilege escalation and lateral movement within network environments. The lack of vendor response despite early disclosure creates additional risk as organizations cannot rely on official patches or updates to address the issue. Organizations should implement immediate network segmentation measures, disable unnecessary web management interfaces, and monitor for suspicious network activity as interim protective measures until firmware updates become available.
The public disclosure of this exploit creates an urgent security concern for all organizations utilizing these router models. Given the remote attack capability and the demonstrated exploit availability, the window for potential exploitation is significant. Network administrators should prioritize identifying all affected devices within their infrastructure and implementing network-level controls to prevent unauthorized access to the web management interfaces. The vulnerability demonstrates the critical importance of timely firmware updates and proactive security monitoring, as the lack of vendor response leaves organizations without official remediation paths. This incident underscores the need for robust vulnerability management processes and the potential risks associated with relying on vendor responsiveness for critical security fixes.