CVE-2025-9252 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 function DisablePasswordAlertRedirect, accessible via the endpoint /goform/DisablePasswordAlertRedirect. An attacker can remotely manipulate the 'hint' argument passed to this function, causing a stack-based buffer overflow. This type of overflow can overwrite the stack memory, potentially allowing arbitrary code execution or crashing the device. The vulnerability requires no user interaction and no authentication, making it remotely exploitable over the network. The CVSS 4.0 score is 8.7 (high), reflecting the ease of exploitation (network attack vector, low complexity, no privileges or user interaction required) and the high impact on confidentiality, integrity, and availability. Although the vendor was notified early, no response or patch has been provided, and while no known exploits are currently reported in the wild, a public exploit is available, increasing the risk of active exploitation. This vulnerability threatens the security of affected Linksys devices, which are commonly used to extend wireless network coverage, potentially allowing attackers to compromise network infrastructure or pivot into internal networks.

For European organizations, this vulnerability poses a significant risk to network security and operational continuity. Linksys range extenders are widely deployed in both enterprise and home office environments across Europe to improve Wi-Fi coverage. Exploitation could lead to unauthorized remote code execution, enabling attackers to intercept or manipulate network traffic, disrupt connectivity, or establish persistent footholds within corporate or residential networks. This can result in data breaches, espionage, lateral movement within networks, and denial of service conditions. Given the lack of vendor patches, organizations face increased exposure, especially those with limited network segmentation or monitoring. The vulnerability's remote exploitability without authentication makes it particularly dangerous in environments where these devices are accessible from untrusted networks or exposed to the internet. Additionally, compromised devices could be leveraged for botnet recruitment or as launch points for further attacks, amplifying the threat landscape for European entities.

1. Immediate network segmentation: Isolate affected Linksys range extenders from critical network segments and restrict their access to management interfaces to trusted internal networks only. 2. Disable remote management features on these devices to prevent external exploitation. 3. Monitor network traffic for unusual activity originating from or targeting these devices, including unexpected outbound connections or anomalous payloads. 4. Implement strict firewall rules to block inbound traffic to the /goform/DisablePasswordAlertRedirect endpoint or related management ports. 5. Where possible, replace vulnerable devices with models from vendors with active security support or that have released patches addressing this vulnerability. 6. If replacement is not immediately feasible, consider deploying virtual patching solutions such as intrusion prevention systems (IPS) that can detect and block exploit attempts targeting this vulnerability. 7. Maintain up-to-date asset inventories to identify all affected devices and prioritize remediation efforts. 8. Engage with Linksys support channels regularly for updates or patches and subscribe to vulnerability advisories for timely information. 9. Educate network administrators about this vulnerability and the importance of securing IoT and network infrastructure devices.