CVE-2025-15234 identifies a critical heap-based buffer overflow vulnerability in the Tenda M3 router firmware version 1.0.0.13(4903). The vulnerability resides in the formSetRemoteInternetLanInfo function, which processes remote requests to the /goform/setInternetLanInfo endpoint. Specifically, the flaw arises from improper handling of input parameters including portIp, portMask, portGateWay, portDns, and portSecDns. An attacker can craft malicious requests that overflow the heap buffer, potentially overwriting adjacent memory and enabling arbitrary code execution or causing a denial of service. The vulnerability is remotely exploitable over the network without any authentication or user interaction, making it highly dangerous. The CVSS 4.0 score of 8.7 reflects its high impact on confidentiality, integrity, and availability, combined with ease of exploitation. Although no patches have been released yet, public exploit code is available, increasing the likelihood of attacks. The vulnerability affects only the specified firmware version, but given the widespread use of Tenda M3 routers in home and small office environments, the attack surface is significant. The lack of authentication and user interaction requirements means attackers can launch attacks at scale, potentially compromising network infrastructure or pivoting to internal networks.

The impact of CVE-2025-15234 is substantial for organizations and individuals using Tenda M3 routers with the vulnerable firmware. Successful exploitation can lead to remote code execution, allowing attackers to take full control of the device. This can result in interception or manipulation of network traffic, installation of persistent malware, or use of the device as a foothold for lateral movement within corporate or home networks. Confidentiality is at risk as attackers may access sensitive data passing through the router. Integrity can be compromised by altering router configurations or injecting malicious payloads. Availability may be affected due to crashes or denial of service caused by the heap overflow. Since the vulnerability requires no authentication, attackers can exploit exposed routers on the internet or within local networks. The public availability of exploit code increases the risk of widespread attacks, including automated scanning and exploitation campaigns. Organizations relying on Tenda M3 devices for critical connectivity may face operational disruptions and data breaches if mitigations are not applied promptly.

To mitigate CVE-2025-15234, organizations should immediately identify all Tenda M3 routers running firmware version 1.0.0.13(4903) within their environment. Since no official patches are currently available, network-level protections are critical. Implement strict firewall rules to block inbound access to the router’s management interfaces, especially the /goform/setInternetLanInfo endpoint, from untrusted networks. Disable remote management features if not required. Employ network segmentation to isolate vulnerable devices from sensitive internal systems. Monitor network traffic for unusual requests targeting the vulnerable endpoint and deploy intrusion detection/prevention systems with signatures for this exploit. Engage with Tenda support channels to obtain updates on patch availability and apply firmware updates as soon as they are released. Additionally, consider replacing vulnerable devices with models that have active security support. Educate users about the risks of exposed router management interfaces and the importance of timely updates. Regularly audit router configurations to ensure no unnecessary services are exposed externally.