CVE-2025-14136 is a stack-based buffer overflow vulnerability identified in several Linksys range extender models (RE6500, RE6250, RE6300, RE6350, RE7000, RE9000) running specific firmware versions (1.0.013.001, 1.0.04.001, 1.0.04.002, 1.1.05.003, 1.2.07.001). The vulnerability resides in the function RE2000v2Repeater_get_wired_clientlist_setClientsName within the mod_form.so module. Specifically, the argument clientsname_0 is improperly handled, allowing an attacker to overflow the stack buffer. This flaw can be exploited remotely over the network without requiring authentication or user interaction, making it highly accessible to attackers. The buffer overflow can lead to arbitrary code execution with elevated privileges on the affected device, potentially allowing attackers to take full control of the device, manipulate network traffic, or pivot to other internal systems. The vendor was contacted early about this issue but has not issued any patches or advisories. A public exploit has been released, increasing the likelihood of active exploitation. The CVSS v4.0 score is 8.7 (high), reflecting the vulnerability's critical impact on confidentiality, integrity, and availability, combined with its ease of exploitation. The affected devices are commonly used in home and small business environments to extend wireless network coverage, but they may also be deployed in enterprise branch offices or critical infrastructure networks, increasing the potential impact of exploitation.

For European organizations, this vulnerability presents a significant risk. Compromise of Linksys range extenders can lead to unauthorized access to internal networks, interception or manipulation of sensitive data, and disruption of network services. Enterprises relying on these devices for network extension or segmentation may face lateral movement by attackers, enabling further compromise of critical systems. The lack of vendor response and patches exacerbates the risk, forcing organizations to rely on workarounds or device replacement. Critical infrastructure sectors such as energy, finance, and government agencies using these devices could experience operational disruptions or data breaches. Additionally, the public availability of exploits increases the threat landscape, making opportunistic attacks more likely. The vulnerability’s remote and unauthenticated nature means attackers can target exposed devices directly over the internet or internal networks, increasing the attack surface. Overall, the threat could lead to significant confidentiality breaches, integrity violations, and availability outages within European organizations.

1. Immediately identify and inventory all Linksys range extenders in use, specifically models RE6500, RE6250, RE6300, RE6350, RE7000, and RE9000 with the affected firmware versions. 2. Isolate vulnerable devices by segmenting them into separate network zones with strict access controls to limit exposure. 3. Disable remote management interfaces and any unnecessary services on these devices to reduce attack vectors. 4. Monitor network traffic for unusual activity originating from or targeting these devices, including attempts to exploit the buffer overflow. 5. Implement network-level protections such as firewalls or intrusion prevention systems with signatures targeting this vulnerability or exploit patterns. 6. Engage with Linksys or authorized vendors for updates or firmware patches; if none are forthcoming, plan for device replacement with secure alternatives. 7. Educate IT staff about the vulnerability and ensure incident response plans include procedures for potential exploitation scenarios. 8. Consider deploying network anomaly detection tools to identify exploitation attempts early. 9. Regularly review and update network device inventories and firmware to prevent similar risks in the future.