CVE-2025-8824 is a high-severity stack-based buffer overflow vulnerability affecting multiple Linksys range extender models, including RE6250, RE6300, RE6350, RE6500, RE7000, and RE9000, with firmware versions up to 20250801. The vulnerability resides in the setRIP function within the /goform/setRIP endpoint. Specifically, the flaw arises from improper handling of the RIPmode and RIPpasswd parameters, which can be manipulated by an attacker to overflow the stack buffer. This overflow can lead to arbitrary code execution or cause the device to crash, resulting in denial of service. The vulnerability is remotely exploitable without requiring user interaction or authentication, making it particularly dangerous. The CVSS v4.0 score is 8.7 (high), reflecting the ease of exploitation (network attack vector, low attack complexity), no privileges or user interaction needed, and a high impact on confidentiality, integrity, and availability. Although the vendor was notified early, no response or patch has been provided, and a public exploit has been disclosed, increasing the risk of active exploitation. The affected devices are commonly used as Wi-Fi range extenders in home and small office environments, often connected to critical network infrastructure, which could allow attackers to pivot into internal networks or intercept sensitive communications.

For European organizations, this vulnerability poses significant risks, especially for small and medium enterprises (SMEs) and home office setups that rely on Linksys range extenders to improve network coverage. Exploitation could lead to unauthorized access to internal networks, data interception, or disruption of network services. Given the remote exploitability without authentication, attackers could compromise devices over the internet or local network, potentially establishing persistent footholds or launching further attacks against corporate assets. The lack of vendor response and patch availability exacerbates the threat, as organizations may be forced to rely on workarounds or device replacement. Additionally, compromised extenders could be used as entry points for espionage or ransomware campaigns targeting European businesses, impacting confidentiality, operational continuity, and trust. The vulnerability also threatens availability by enabling denial-of-service conditions through device crashes. The widespread use of these Linksys models in Europe, combined with the public exploit disclosure, increases the urgency for mitigation to prevent exploitation in the region.

1. Immediate mitigation should include isolating affected Linksys extenders from critical network segments and restricting remote management access, especially from untrusted networks. 2. Disable or restrict access to the /goform/setRIP endpoint if possible, using firewall rules or device configuration settings. 3. Monitor network traffic for unusual requests targeting the RIPmode or RIPpasswd parameters to detect potential exploitation attempts. 4. Where feasible, replace vulnerable devices with models from vendors that provide timely security updates and have no known vulnerabilities. 5. Implement network segmentation to limit the impact of a compromised extender and prevent lateral movement. 6. Employ intrusion detection/prevention systems (IDS/IPS) with signatures or heuristics tuned to detect buffer overflow attempts against Linksys extenders. 7. Maintain up-to-date inventories of network devices to quickly identify and remediate vulnerable hardware. 8. Engage with Linksys support channels to seek updates or official guidance, and monitor security advisories for any forthcoming patches. 9. Educate IT staff and users about the risks associated with these devices and the importance of network hygiene and monitoring.