CVE-2025-6148 is a critical buffer overflow vulnerability identified in the TOTOLINK A3002RU router, specifically affecting firmware version 3.0.0-B20230809.1615. The vulnerability arises from improper handling of the HTTP POST request to the /boafrm/formSysLog endpoint, where manipulation of the 'submit-url' argument can trigger a buffer overflow condition. This flaw allows an unauthenticated remote attacker to send specially crafted HTTP POST requests that overflow internal buffers, potentially leading to arbitrary code execution or denial of service. The vulnerability does not require user interaction or prior authentication, making it highly exploitable over the network. The CVSS 4.0 score of 8.7 reflects high severity, with network attack vector, low attack complexity, no privileges required, and no user interaction needed. The impact on confidentiality, integrity, and availability is rated as high, indicating potential full compromise of the affected device. While no public exploits have been confirmed in the wild yet, the public disclosure of the vulnerability increases the risk of exploitation attempts. TOTOLINK A3002RU is a consumer and small office/home office (SOHO) router, and such devices are often deployed in various environments, including European households and small businesses. The vulnerability could be leveraged to gain persistent access to internal networks, intercept or manipulate traffic, or pivot to other systems within the network.

For European organizations, especially small and medium enterprises (SMEs) and residential users relying on TOTOLINK A3002RU routers, this vulnerability poses a significant risk. Exploitation could lead to unauthorized network access, data interception, and disruption of internet connectivity. Given the router's role as a network gateway, attackers could use this vulnerability to establish backdoors, launch further attacks on internal systems, or exfiltrate sensitive information. The high severity and ease of exploitation increase the likelihood of targeted attacks or opportunistic scanning campaigns. Critical infrastructure or organizations with remote offices using these routers may face operational disruptions and data breaches. The lack of available patches at the time of disclosure exacerbates the risk, potentially leaving many devices exposed for an extended period. Additionally, the vulnerability could be exploited as part of botnet recruitment or distributed denial-of-service (DDoS) attacks, impacting broader network stability in Europe.

1. Immediate Network Segmentation: Isolate TOTOLINK A3002RU devices from critical internal networks to limit potential lateral movement if compromised. 2. Disable Remote Management: Turn off remote HTTP management interfaces on the router to reduce exposure to external attacks. 3. Monitor Network Traffic: Implement IDS/IPS solutions to detect anomalous HTTP POST requests targeting /boafrm/formSysLog or unusual traffic patterns indicative of exploitation attempts. 4. Firmware Updates: Although no patches are currently available, maintain close communication with TOTOLINK for firmware updates addressing this vulnerability and apply them promptly once released. 5. Access Control: Restrict management access to the router to trusted IP addresses and use VPNs for remote administration where possible. 6. Device Replacement: For high-risk environments where patching is delayed, consider replacing affected routers with models from vendors with timely security support. 7. Incident Response Preparation: Prepare to respond to potential compromises by backing up configurations, logging router activity, and having remediation plans ready. 8. User Awareness: Educate users about the risks of using vulnerable routers and encourage reporting of unusual network behavior.