CVE-2025-55591 is a command injection vulnerability identified in the TOTOLINK A3002R router firmware version 4.0.0-B20230531.1404. The vulnerability exists in the 'devicemac' parameter of the 'formMapDel' endpoint. Command injection vulnerabilities allow an attacker to execute arbitrary commands on the underlying operating system with the privileges of the affected application. In this case, the vulnerable parameter likely fails to properly sanitize user input, enabling malicious actors to inject shell commands. Exploiting this flaw could allow attackers to gain unauthorized control over the router, manipulate network traffic, disrupt services, or pivot to other devices on the network. Although no known exploits are currently reported in the wild, the lack of a patch and the critical nature of command injection vulnerabilities make this a significant risk. The absence of a CVSS score indicates that the vulnerability is newly disclosed and has not yet undergone formal severity assessment. The TOTOLINK A3002R is a consumer-grade router commonly used in home and small office environments, which may lack robust security monitoring, increasing the risk of exploitation.

For European organizations, particularly small and medium enterprises (SMEs) and home office users relying on TOTOLINK A3002R routers, this vulnerability poses a serious threat. Successful exploitation could lead to complete compromise of the router, enabling attackers to intercept or manipulate network traffic, launch further attacks within the internal network, or disrupt internet connectivity. This could result in data breaches, loss of confidentiality, integrity violations, and availability issues. Given the router's role as a network gateway, the impact extends beyond the device itself to all connected systems. In sectors with sensitive data or critical operations, such as healthcare, finance, or government, the consequences could be severe. Additionally, compromised routers could be co-opted into botnets for distributed denial-of-service (DDoS) attacks, further amplifying the threat landscape in Europe.

Immediate mitigation steps include isolating affected TOTOLINK A3002R devices from critical networks until a firmware update is available. Network administrators should monitor router logs and network traffic for unusual activity indicative of exploitation attempts. Implement network segmentation to limit the impact of a compromised device. Disable remote management features if enabled, especially those accessible from the internet. Employ strong authentication and change default credentials on all routers. Since no patch is currently available, consider replacing vulnerable devices with models from vendors with a proven security track record. Additionally, organizations should implement intrusion detection systems (IDS) capable of detecting command injection patterns and anomalous router behavior. Regularly check the vendor’s website and trusted vulnerability databases for firmware updates addressing this issue.