CVE-2025-9481 in RE6250
Summary
by MITRE • 08/26/2025
A security vulnerability has been detected in Linksys RE6250, RE6300, RE6350, RE6500, RE7000 and RE9000 1.0.013.001/1.0.04.001/1.0.04.002/1.1.05.003/1.2.07.001. This affects the function setIpv6 of the file /goform/setIpv6. The manipulation of the argument tunrd_Prefix leads to stack-based buffer overflow. Remote exploitation of the attack is possible. The exploit has been disclosed publicly 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 • 08/29/2025
This vulnerability resides within the Linksys router firmware versions 1.0.013.001 through 1.2.07.001 affecting multiple models including RE6250, RE6300, RE6350, RE6500, RE7000, and RE9000. The flaw manifests in the setIpv6 function located at /goform/setIpv6 which processes IPv6 configuration parameters. The specific vulnerability occurs when handling the tunrd_Prefix argument, creating a stack-based buffer overflow condition that can be exploited remotely. This represents a critical security weakness that allows attackers to execute arbitrary code on affected devices with potentially full system compromise. The vulnerability falls under CWE-121 Stack-based Buffer Overflow, which is classified as a fundamental memory corruption issue that can lead to complete system control.
The technical implementation of this vulnerability involves the improper handling of user-supplied input within the IPv6 prefix configuration parameter. When an attacker sends a specially crafted request to the setIpv6 endpoint with an oversized tunrd_Prefix value, the firmware fails to properly validate or bound-check the input before copying it into a fixed-size stack buffer. This overflow allows the attacker to overwrite adjacent stack memory, potentially corrupting program execution flow and enabling remote code execution. The attack vector is particularly concerning as it requires no authentication and can be executed over the network, making it accessible to any attacker with knowledge of the affected firmware versions.
The operational impact of this vulnerability extends beyond simple remote code execution to encompass complete network infrastructure compromise. Once exploited, attackers can gain root access to the router, allowing them to modify network configurations, intercept traffic, establish persistent backdoors, or use the device as a pivot point for attacking other systems within the network. This vulnerability directly maps to ATT&CK technique T1059.007 Command and Scripting Interpreter: Unix Shell and T1078 Valid Accounts, as it enables attackers to execute arbitrary commands and potentially escalate privileges. The affected devices serve as critical network infrastructure points, making this vulnerability particularly dangerous for enterprise and home network environments where these routers are commonly deployed.
Given the public disclosure and availability of exploit code, immediate remediation is essential. Organizations should prioritize firmware updates from Linksys if available, though the vendor's lack of response to early disclosure concerns raises questions about the availability of patches. Network segmentation and access controls should be implemented to limit exposure, while monitoring for unusual network traffic patterns or unauthorized configuration changes can help detect exploitation attempts. The vulnerability demonstrates the importance of proper input validation and bounds checking in embedded systems, as well as the critical need for vendors to maintain responsive security disclosure practices. Security teams should also consider implementing network intrusion detection systems to monitor for exploitation attempts targeting this specific vulnerability.