CVE-2025-44838 is a command injection vulnerability identified in the TOTOLINK CPE CP900 router firmware version V6.3c.1144_B20190715. The vulnerability exists in the setUploadUserData function, specifically via the FileName parameter. An attacker can exploit this flaw by sending a crafted request that manipulates the FileName parameter to execute arbitrary system commands on the affected device. This type of vulnerability is classified under CWE-77 (Improper Neutralization of Special Elements used in a Command), which typically allows attackers to inject operating system commands that the application executes without proper sanitization or validation. The CVSS 3.1 base score is 6.3, indicating a medium severity level. The vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L) reveals that the attack can be performed remotely over the network (AV:N) with low attack complexity (AC:L), but requires privileges (PR:L) on the device, and no user interaction (UI:N). The impact affects confidentiality, integrity, and availability at a low level, meaning the attacker can potentially access some data, alter system behavior, or disrupt services, but not to a critical extent. No known public exploits are reported yet, and no patches have been linked, indicating that affected users should be vigilant and apply updates once available. TOTOLINK CPE CP900 is a consumer-grade router, often used in small office/home office (SOHO) environments, which can serve as a gateway to internal networks if compromised. The vulnerability allows attackers to gain command execution capabilities, which could lead to further network intrusion, data exfiltration, or persistent access if exploited successfully.

For European organizations, especially small and medium enterprises (SMEs) and home users relying on TOTOLINK CPE CP900 routers, this vulnerability poses a moderate risk. Exploitation could allow attackers to execute arbitrary commands on the router, potentially leading to unauthorized access to internal networks, interception or manipulation of network traffic, and disruption of internet connectivity. This could compromise sensitive business data, enable lateral movement within corporate networks, or facilitate the deployment of malware such as botnets or ransomware. Given the router’s role as a network gateway, successful exploitation could undermine network perimeter defenses. While the requirement for low-level privileges reduces the ease of exploitation, many routers have default or weak credentials, increasing the likelihood of privilege acquisition. The lack of user interaction needed means automated attacks could be feasible once credentials are obtained. The absence of known exploits in the wild currently limits immediate widespread impact, but the vulnerability’s presence in widely deployed consumer devices means that targeted attacks against European SMEs or home offices could increase, especially in sectors with valuable intellectual property or critical infrastructure connections.

Immediately audit all TOTOLINK CPE CP900 devices within the organization to identify affected firmware versions (V6.3c.1144_B20190715). Change default or weak administrative credentials on all affected routers to strong, unique passwords to reduce the risk of privilege escalation required for exploitation. Restrict remote management access to the router’s administrative interface by disabling WAN-side management or limiting access to trusted IP addresses only. Implement network segmentation to isolate SOHO or consumer-grade routers from critical internal networks, minimizing potential lateral movement if compromised. Monitor network traffic for unusual outbound connections or command-and-control indicators that may suggest exploitation attempts. Apply firmware updates or patches from TOTOLINK as soon as they become available; if no official patch exists, consider replacing vulnerable devices with models from vendors with stronger security track records. Deploy intrusion detection/prevention systems (IDS/IPS) with signatures or heuristics capable of detecting command injection attempts targeting router management interfaces. Educate users and administrators about the risks of exposing router management interfaces and the importance of secure configuration practices.