CVE-2025-15218 is a buffer overflow vulnerability identified in the Tenda AC10U router firmware versions 15.03.06.48 and 15.03.06.49. The vulnerability resides in the function fromadvsetlanip within the /goform/AdvSetLanip component, which handles POST request parameters. Specifically, the lanMask argument is improperly validated, allowing an attacker to craft a malicious POST request that triggers a buffer overflow condition. This flaw can be exploited remotely without requiring authentication or user interaction, making it highly accessible to attackers. The buffer overflow can lead to memory corruption, enabling arbitrary code execution or causing the device to crash, resulting in denial of service. The vulnerability has a CVSS 4.0 base score of 8.7, reflecting its high impact on confidentiality, integrity, and availability. Although no active exploitation has been reported in the wild, a public exploit is available, increasing the likelihood of attacks. The vulnerability affects a widely deployed consumer and small business router model, which is often used as a gateway device, making it a critical target for attackers seeking network access or disruption.

The impact of CVE-2025-15218 is significant for organizations and individuals using the Tenda AC10U routers. Successful exploitation can lead to full compromise of the affected device, allowing attackers to execute arbitrary code with elevated privileges. This can result in unauthorized access to internal networks, interception or manipulation of network traffic, and disruption of network services through denial of service. For enterprises, this could mean exposure of sensitive data, lateral movement within corporate networks, and potential use of compromised routers as footholds for further attacks. For ISPs or managed service providers deploying these routers at scale, widespread exploitation could lead to large-scale network outages or data breaches. The remote, unauthenticated nature of the exploit increases the risk of automated attacks and worm-like propagation. The availability of a public exploit further elevates the threat level, as less skilled attackers can leverage it to compromise vulnerable devices.

1. Immediately check for firmware updates from Tenda addressing this vulnerability and apply patches to all affected AC10U devices. 2. If patches are not yet available, restrict remote access to the router’s management interface by disabling WAN-side administration or limiting access via firewall rules. 3. Implement network segmentation to isolate vulnerable routers from critical infrastructure and sensitive data. 4. Monitor network traffic for unusual POST requests targeting /goform/AdvSetLanip or anomalous patterns indicative of exploitation attempts. 5. Employ intrusion detection/prevention systems (IDS/IPS) with signatures or heuristics capable of detecting buffer overflow attempts against Tenda routers. 6. Educate users and administrators about the risk and encourage prompt reporting of any unusual router behavior or network disruptions. 7. Consider replacing affected devices with models from vendors with a stronger security track record if patching is delayed or infeasible. 8. Regularly audit router configurations to ensure default credentials are changed and unnecessary services are disabled to reduce attack surface.