CVE-2025-9253 is a high-severity stack-based buffer overflow vulnerability affecting multiple Linksys range extender models including RE6250, RE6300, RE6350, RE6500, RE7000, and RE9000 running firmware versions 1.0.013.001, 1.0.04.001, 1.0.04.002, 1.1.05.003, and 1.2.07.001. The vulnerability resides in the RP_doSpecifySiteSurvey function within the /goform/RP_doSpecifySiteSurvey endpoint. Specifically, the issue arises from improper handling of the ssidhex argument, which can be manipulated by an attacker to trigger a stack-based buffer overflow. This type of vulnerability can lead to arbitrary code execution or denial of service on the affected device. The attack vector is remote and does not require user interaction or prior authentication, making exploitation relatively straightforward. The vendor, Linksys, was notified early but has not issued any response or patch, increasing the risk exposure. The CVSS 4.0 base score is 8.7, reflecting the high impact on confidentiality, integrity, and availability, combined with low attack complexity and no required privileges or user interaction. Although no known exploits are currently reported in the wild, the public disclosure of the vulnerability and availability of technical details raise the likelihood of future exploitation attempts targeting these devices.

For European organizations, the impact of this vulnerability can be significant, especially for enterprises and service providers relying on Linksys range extenders to expand wireless network coverage. Successful exploitation could allow attackers to execute arbitrary code on the device, potentially gaining a foothold within internal networks. This could lead to interception or manipulation of network traffic, lateral movement, and compromise of sensitive data. Additionally, disruption of network availability through denial-of-service conditions could affect business operations. Given the remote attack vector and lack of authentication requirements, attackers can target vulnerable devices over the internet or local networks without user involvement. This is particularly concerning for organizations with remote or branch offices using these devices without strict network segmentation or monitoring. The absence of vendor patches further exacerbates the risk, forcing organizations to rely on mitigation strategies or device replacement to maintain security posture.

1. Immediate mitigation should include isolating affected Linksys range extenders from critical network segments and restricting access to their management interfaces via firewall rules or network segmentation. 2. Disable or restrict remote management features if enabled, to reduce exposure to external attackers. 3. Monitor network traffic for unusual activity or attempts to access the /goform/RP_doSpecifySiteSurvey endpoint with suspicious payloads. 4. Where possible, replace affected devices with models from vendors that provide timely security updates. 5. If replacement is not immediately feasible, implement strict access controls limiting device management to trusted internal IP addresses only. 6. Regularly audit network devices for firmware versions and maintain an inventory to quickly identify vulnerable units. 7. Engage with Linksys support channels to seek official patches or guidance and subscribe to vulnerability advisories for updates. 8. Consider deploying intrusion detection/prevention systems (IDS/IPS) with signatures targeting exploitation attempts of this vulnerability.