CVE-2025-11388 is a stack-based buffer overflow vulnerability identified in the Tenda AC15 router firmware version 15.03.05.18. The vulnerability resides in an unspecified function within the /goform/setNotUpgrade endpoint, specifically through manipulation of the 'newVersion' parameter. When this parameter is crafted maliciously, it causes a stack overflow, which can overwrite the return address or other control data on the stack, enabling an attacker to execute arbitrary code remotely. The vulnerability requires no authentication and no user interaction, making it highly exploitable over the network. The CVSS 4.0 vector indicates network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:L), no user interaction (UI:N), and high impact on confidentiality, integrity, and availability (VC:H/VI:H/VA:H). Although no exploits have been observed in the wild yet, publicly available proof-of-concept exploits increase the likelihood of future attacks. The vulnerability affects a widely used consumer and small business router model, which is often deployed in home and office networks. Exploitation could lead to full device compromise, allowing attackers to intercept, modify, or disrupt network traffic, or pivot into internal networks. The lack of an official patch at the time of disclosure necessitates interim mitigations to reduce exposure.

For European organizations, the impact of CVE-2025-11388 can be significant, especially for small and medium enterprises or home office setups relying on Tenda AC15 routers. Successful exploitation could lead to complete compromise of the router, allowing attackers to intercept sensitive communications, deploy malware, or use the device as a foothold for lateral movement within corporate networks. This threatens confidentiality by exposing internal data, integrity by allowing manipulation of network traffic, and availability by potentially causing device crashes or denial of service. Critical infrastructure or organizations with remote workforce setups using vulnerable devices are particularly at risk. The exploitability without authentication and user interaction increases the threat level, potentially enabling widespread automated attacks. The absence of patches at disclosure time means organizations must rely on network segmentation and access controls to mitigate risk. The presence of publicly available exploits may accelerate attack campaigns targeting European networks.

1. Immediately isolate Tenda AC15 devices running firmware version 15.03.05.18 from untrusted networks, especially the internet, to prevent remote exploitation. 2. Monitor vendor communications closely for official firmware updates or patches addressing CVE-2025-11388 and apply them promptly upon release. 3. Implement network-level protections such as firewall rules or intrusion prevention systems to block or restrict access to the /goform/setNotUpgrade endpoint or suspicious HTTP requests targeting the router's management interface. 4. Employ network segmentation to separate vulnerable devices from critical infrastructure and sensitive data environments. 5. Conduct regular network traffic analysis to detect anomalous activities indicative of exploitation attempts, such as unusual POST requests to the vulnerable endpoint. 6. Educate users and administrators about the risks and signs of router compromise to enable rapid incident response. 7. Consider replacing vulnerable Tenda AC15 devices with models from vendors with stronger security track records if patching is delayed or unavailable. 8. Use VPNs or secure remote access solutions that do not rely solely on vulnerable routers for perimeter defense.