CVE-2025-15231 identifies a stack-based buffer overflow vulnerability in the Tenda M3 router firmware version 1.0.0.13(4903). The flaw exists in the formSetRemoteVlanInfo function, which processes requests to the /goform/setVlanInfo endpoint. Specifically, improper validation or bounds checking of the input parameters ID, vlan, and port allows an attacker to overflow a stack buffer. This overflow can corrupt the stack, potentially overwriting the return address or other control data, enabling arbitrary code execution or denial of service. The vulnerability is remotely exploitable over the network without requiring authentication or user interaction, significantly increasing its risk profile. The CVSS 4.0 vector indicates low attack complexity, no privileges required, and no user interaction needed, with high impact on confidentiality, integrity, and availability. While no exploits have been observed in the wild yet, the public disclosure of exploit details raises the likelihood of imminent attacks. This vulnerability affects a widely deployed consumer and small business router model, which may be used in various organizational environments. The lack of an official patch at the time of disclosure necessitates interim mitigations to prevent exploitation.

For European organizations, exploitation of this vulnerability could lead to severe consequences including unauthorized remote code execution on network routers, resulting in full device compromise. Attackers could intercept, modify, or redirect network traffic, undermining confidentiality and integrity of sensitive communications. Availability may also be impacted through denial-of-service conditions caused by crashes or malicious payloads. Organizations relying on Tenda M3 routers for critical network functions or as part of their perimeter security could face network outages or persistent backdoors. This risk extends to small and medium enterprises and home office setups that use these devices, potentially serving as entry points for broader network intrusions. The public availability of exploit information increases the urgency for European entities to assess exposure and implement mitigations to protect their network infrastructure.

1. Immediately inventory all Tenda M3 routers running firmware version 1.0.0.13(4903) within the organization. 2. Monitor Tenda’s official channels for firmware updates addressing CVE-2025-15231 and apply patches promptly upon release. 3. Until patches are available, restrict network access to the router’s management interface (/goform/setVlanInfo) by implementing firewall rules or access control lists limiting connections to trusted administrative hosts only. 4. Disable remote management features if not strictly necessary to reduce exposure. 5. Employ network intrusion detection/prevention systems (IDS/IPS) with signatures or heuristics capable of detecting attempts to exploit this buffer overflow. 6. Conduct regular network traffic analysis to identify anomalous requests targeting the vulnerable endpoint. 7. Educate IT staff about the vulnerability and the importance of rapid response to suspicious router behavior. 8. Consider network segmentation to isolate vulnerable devices from critical assets. 9. Maintain backups of router configurations and logs to support incident response if exploitation occurs.