CVE-2025-12225 is a stack-based buffer overflow vulnerability identified in the Tenda AC6 router firmware version 15.03.06.50. The vulnerability arises from improper handling of the shareSpeed parameter in the HTTP request handler component, specifically at the /goform/WifiGuestSet endpoint. When this argument is manipulated with crafted input, it causes a stack buffer overflow, which can overwrite critical memory regions. This flaw can be exploited remotely over the network without requiring authentication or user interaction, making it highly accessible to attackers. Successful exploitation could lead to arbitrary code execution with elevated privileges on the device, potentially allowing attackers to take full control of the router. This could enable interception or manipulation of network traffic, disruption of network services, or use of the device as a foothold for further attacks within the network. The CVSS 4.0 base score is 8.7, reflecting the high impact on confidentiality, integrity, and availability, combined with low attack complexity and no requirement for privileges or user interaction. Although no confirmed exploits in the wild have been reported, the public disclosure of exploit details increases the likelihood of active exploitation attempts. The vulnerability affects a widely deployed consumer-grade router, which is commonly used in home and small office environments, amplifying its potential impact.

The impact of CVE-2025-12225 is significant for organizations and individuals using the Tenda AC6 router with the vulnerable firmware. Exploitation can lead to full compromise of the router, allowing attackers to intercept, modify, or redirect network traffic, which threatens confidentiality and integrity of data. Attackers could disrupt network availability by causing device crashes or reboots. Compromised routers may also be leveraged as entry points for lateral movement within corporate or home networks, facilitating further attacks such as data exfiltration, malware deployment, or persistent espionage. Given the router's role as a network gateway, the vulnerability could affect all devices behind it, magnifying the scope of impact. The ease of remote exploitation without authentication increases the risk of widespread attacks, especially in environments where firmware updates are not promptly applied. This vulnerability could also be exploited in botnet campaigns or as part of broader cyberattack campaigns targeting consumer networking equipment.

To mitigate CVE-2025-12225, organizations and users should immediately check for and apply any official firmware updates released by Tenda addressing this vulnerability. If no patch is available, users should consider temporary mitigations such as disabling remote management interfaces or restricting access to the router's web interface to trusted internal IP addresses only. Network segmentation can limit exposure by isolating vulnerable devices from critical systems. Monitoring network traffic for unusual activity targeting the /goform/WifiGuestSet endpoint can help detect exploitation attempts. Employing intrusion detection/prevention systems (IDS/IPS) with signatures for this vulnerability can provide additional defense. Users should also change default credentials and ensure strong authentication mechanisms are in place to reduce risk from other attack vectors. Finally, organizations should plan for rapid deployment of patches and maintain an inventory of affected devices to prioritize remediation efforts.