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, specifically in 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. An attacker can remotely exploit this flaw by manipulating the ssidhex argument, causing a stack-based buffer overflow. This type of overflow can overwrite the call stack, potentially allowing arbitrary code execution, denial of service, or system compromise. The vulnerability requires no user interaction and no authentication, making it remotely exploitable over the network. The CVSS 4.0 score of 8.7 reflects the high impact on confidentiality, integrity, and availability, with low attack complexity and no privileges required. Although the vendor was notified early, no response or patch has been issued, and while no known exploits are currently observed in the wild, public disclosure of the exploit code increases the risk of imminent attacks. This vulnerability is critical for network security as these devices often serve as wireless access points or extenders, and compromise could lead to lateral movement within networks or interception of sensitive communications.

For European organizations, this vulnerability poses a significant risk to network infrastructure security. Linksys range extenders are commonly used in both enterprise and residential environments across Europe to enhance Wi-Fi coverage. Exploitation could lead to unauthorized access to internal networks, data exfiltration, or disruption of wireless services. Critical sectors such as finance, healthcare, and government agencies that rely on secure and stable wireless connectivity could face operational disruptions or data breaches. Additionally, compromised devices could be leveraged as pivot points for broader attacks, including ransomware or espionage campaigns. The lack of vendor response and patches exacerbates the threat, leaving organizations exposed. Given the remote exploitability without authentication, attackers can target vulnerable devices from anywhere, increasing the attack surface. The potential for high confidentiality, integrity, and availability impact makes this vulnerability particularly dangerous for European organizations with sensitive data and compliance obligations under regulations like GDPR.

Organizations should immediately inventory their network infrastructure to identify any affected Linksys range extender models and firmware versions. Since no official patches are available, mitigation should focus on network-level controls: isolate vulnerable devices on segmented VLANs with strict access controls, disable remote management interfaces if not required, and restrict inbound traffic to these devices using firewalls. Monitoring network traffic for unusual activity related to the /goform/RP_doSpecifySiteSurvey endpoint or malformed ssidhex parameters can help detect exploitation attempts. Where possible, replace affected devices with models from vendors that provide timely security updates. Additionally, implement network intrusion detection/prevention systems (IDS/IPS) with signatures tuned to detect buffer overflow attempts targeting Linksys devices. Regularly review vendor communications for updates or patches. Educate IT staff on this vulnerability to ensure rapid response to any suspicious activity. Finally, consider deploying network segmentation and zero-trust principles to limit the impact of any potential compromise.