CVE-2025-9748 is a high-severity stack-based buffer overflow vulnerability identified in the Tenda CH22 router, specifically version 1.0.0.1. The flaw exists in the function fromIpsecitem within the /goform/IPSECsave component of the embedded HTTP daemon (httpd). The vulnerability arises when an attacker remotely manipulates the 'ipsecno' argument, leading to a stack-based buffer overflow condition. This type of vulnerability can allow an attacker to overwrite the stack memory, potentially enabling arbitrary code execution, denial of service, or system compromise. The attack vector is remote and does not require user interaction, but it does require low privileges (PR:L) on the network, indicating that the attacker must have network access to the device's management interface. The CVSS 4.0 base score is 8.7, reflecting the high impact on confidentiality, integrity, and availability, with no scope change. The vulnerability is exploitable without authentication (AT:N) and with low attack complexity (AC:L). Although no known exploits are currently reported in the wild, the nature of the vulnerability and its remote exploitability make it a significant risk for affected devices. The absence of patches at the time of publication increases the urgency for mitigation. The Tenda CH22 is a network device commonly used in small office/home office (SOHO) environments, and exploitation could lead to full device compromise, enabling attackers to intercept or manipulate network traffic, disrupt services, or pivot into internal networks.

For European organizations, especially small and medium enterprises (SMEs) and home office users relying on Tenda CH22 routers, this vulnerability poses a substantial risk. Successful exploitation could lead to full compromise of the router, resulting in interception of sensitive communications, unauthorized network access, and potential lateral movement within corporate networks. This could impact confidentiality through data leakage, integrity by altering network traffic or configurations, and availability by causing device crashes or denial of service. Given the router's role as a network gateway, compromised devices could serve as persistent footholds for attackers, undermining organizational security. Additionally, critical infrastructure or remote sites using these devices may face operational disruptions. The lack of current exploits in the wild does not diminish the threat, as the vulnerability's characteristics make it a likely target for future attacks. European organizations with limited IT security resources may be particularly vulnerable due to challenges in timely detection and remediation.

1. Immediate network segmentation: Isolate Tenda CH22 devices from critical network segments to limit potential lateral movement if compromised. 2. Restrict remote management access: Disable or tightly control remote access to the router's management interface, preferably limiting it to trusted IP addresses or VPN connections. 3. Monitor network traffic for anomalies: Deploy IDS/IPS solutions to detect unusual patterns that may indicate exploitation attempts targeting the /goform/IPSECsave endpoint. 4. Implement strict firewall rules: Block unsolicited inbound traffic to the router's management ports from untrusted networks. 5. Vendor engagement: Actively monitor Tenda's official channels for patches or firmware updates addressing CVE-2025-9748 and apply them promptly upon release. 6. Device replacement consideration: For environments where patching is delayed or unavailable, consider replacing affected devices with models from vendors with robust security update practices. 7. Incident response readiness: Prepare to respond to potential exploitation by maintaining backups of router configurations and having procedures to reset or reimage devices if compromise is suspected.