CVE-2025-12260 identifies a stack-based buffer overflow vulnerability in the TOTOLINK A3300R router firmware version 17.0.0cu.557_B20221024. The vulnerability resides in the setSyslogCfg function of the /cgi-bin/cstecgi.cgi CGI script, which processes POST requests. Specifically, the 'enable' parameter is not properly validated or bounded, allowing an attacker to supply an oversized input that overflows the stack buffer. This overflow can corrupt the execution stack, enabling arbitrary code execution with elevated privileges on the device. The vulnerability is remotely exploitable over the network without requiring authentication or user interaction, making it highly accessible to attackers. The CVSS 4.0 base score is 8.7, reflecting the critical nature of remote code execution with high impact on confidentiality, integrity, and availability. Although no known exploits are currently active in the wild, the public disclosure of exploit details increases the likelihood of exploitation attempts. The TOTOLINK A3300R is a consumer and small business router, and compromise could allow attackers to intercept or manipulate network traffic, disrupt services, or use the device as a foothold for further attacks within organizational networks.

For European organizations, exploitation of CVE-2025-12260 could result in severe consequences including unauthorized remote code execution on network routers, leading to full compromise of the device. This can enable attackers to intercept sensitive communications, manipulate network traffic, deploy malware, or disrupt network availability. Small and medium enterprises relying on TOTOLINK A3300R routers for critical connectivity may face operational disruptions and data breaches. Additionally, compromised routers could be leveraged as pivot points for lateral movement within corporate networks or as part of botnets targeting other infrastructure. The impact is particularly critical for sectors with stringent data protection requirements such as finance, healthcare, and government agencies. The lack of authentication and user interaction requirements lowers the barrier for attackers, increasing the risk of widespread exploitation. The vulnerability also poses risks to home users who may be part of supply chains or remote work environments connected to European organizations.

1. Immediately check for and apply any firmware updates or patches released by TOTOLINK addressing CVE-2025-12260. 2. If patches are not yet available, restrict access to the router’s management interface by implementing network segmentation and firewall rules to limit exposure to trusted IP addresses only. 3. Disable remote management features unless absolutely necessary, and if enabled, enforce strong authentication and use VPN tunnels for remote access. 4. Monitor network traffic for unusual activity or signs of exploitation attempts targeting the /cgi-bin/cstecgi.cgi endpoint. 5. Employ intrusion detection/prevention systems (IDS/IPS) with signatures or heuristics capable of detecting buffer overflow attempts against this router model. 6. Conduct regular security audits and vulnerability scans on network devices to identify unpatched or vulnerable firmware versions. 7. Educate IT staff and users about the risks of using outdated router firmware and the importance of timely updates. 8. Consider replacing affected devices with models from vendors with stronger security track records if timely patching is not feasible.