CVE-2025-12210 is a stack-based buffer overflow vulnerability identified in the Tenda O3 router firmware version 1.0.0.10(2478). The flaw exists in the SetValue and GetValue functions within the /goform/AdvSetLanip endpoint, which processes the lanIp parameter. Improper validation or bounds checking of this parameter allows an attacker to overwrite the stack memory, potentially leading to arbitrary code execution or device crash. The vulnerability is remotely exploitable without requiring user interaction or prior authentication, making it highly accessible to attackers. The CVSS v4.0 score is 8.7 (high severity), reflecting the vulnerability's network attack vector, low complexity, no privileges required, and no user interaction needed. The impact on confidentiality, integrity, and availability is high, as successful exploitation could allow attackers to take full control of the device, intercept or manipulate network traffic, or disrupt network services. Although no confirmed exploits are currently observed in the wild, a public exploit is available, increasing the likelihood of exploitation attempts. The vulnerability affects a widely deployed consumer and small business router model, which may be present in European organizations' network infrastructure. No official patches or firmware updates have been linked yet, emphasizing the need for immediate mitigation strategies.

For European organizations, this vulnerability poses a significant risk to network security and operational continuity. Compromise of Tenda O3 routers could lead to unauthorized access to internal networks, interception of sensitive data, and disruption of critical services. Small and medium enterprises (SMEs) and home offices using these devices are particularly vulnerable due to limited security monitoring and patch management capabilities. The ability to exploit the vulnerability remotely without authentication means attackers can launch attacks from anywhere, increasing the threat surface. Potential impacts include data breaches, lateral movement within corporate networks, and denial of service conditions. Given the public availability of exploits, attackers may quickly weaponize this vulnerability for targeted attacks or widespread campaigns. The lack of official patches increases the urgency for organizations to implement compensating controls to protect their network perimeter and internal assets.

1. Immediately identify and inventory all Tenda O3 devices running firmware version 1.0.0.10(2478) within the network. 2. Monitor vendor communications for official firmware updates or patches addressing CVE-2025-12210 and apply them promptly upon release. 3. Implement network-level protections such as firewall rules or intrusion prevention systems (IPS) to block or alert on suspicious HTTP requests targeting the /goform/AdvSetLanip endpoint. 4. Restrict remote management access to Tenda O3 devices by limiting access to trusted IP addresses or disabling remote administration if not required. 5. Employ network segmentation to isolate vulnerable devices from critical infrastructure and sensitive data environments. 6. Conduct regular network traffic analysis to detect anomalous patterns indicative of exploitation attempts. 7. Educate IT staff about this vulnerability and the importance of rapid response to emerging threats. 8. Consider replacing vulnerable devices with models from vendors with stronger security track records if patching is delayed or unavailable.