CVE-2025-46631 is a medium-severity vulnerability affecting the Tenda RX2 Pro router firmware version 16.03.30.14. The issue stems from improper access controls in the router's web management portal, specifically allowing an unauthenticated remote attacker to enable Telnet access on the router's operating system by sending a crafted HTTP request to the /goform/telnet endpoint. This vulnerability is classified under CWE-287 (Improper Authentication), indicating that the affected system fails to properly verify the identity or privileges of the requester before granting access to sensitive functionality. The vulnerability requires no authentication or user interaction, and can be exploited remotely over the network, as the web management portal is typically exposed on the local network or potentially on the WAN interface if remote management is enabled. The CVSS 3.1 base score is 6.5 (medium), with vector AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N, indicating network attack vector, low attack complexity, no privileges or user interaction required, unchanged scope, and low impact on confidentiality and integrity, with no impact on availability. Exploiting this vulnerability allows an attacker to enable Telnet access, which is often disabled by default due to its insecure nature. Once Telnet is enabled, an attacker may attempt further exploitation such as brute forcing credentials or executing arbitrary commands if default or weak credentials are present. Although no known exploits are currently reported in the wild, the vulnerability presents a significant risk due to the ease of exploitation and potential for lateral movement or persistent access within affected networks.

For European organizations, this vulnerability poses a risk primarily to network infrastructure security. The Tenda RX2 Pro router is a consumer and small office/home office (SOHO) device, and its presence in enterprise environments may be limited but not negligible, especially in smaller businesses or branch offices. Enabling Telnet access remotely without authentication could allow attackers to gain unauthorized access to the router's OS, potentially leading to interception or manipulation of network traffic, deployment of malware, or pivoting to internal systems. Confidentiality and integrity of network communications could be compromised, although availability impact is minimal. The risk is heightened in organizations that expose router management interfaces to the internet or fail to change default credentials. Given the router's market penetration in European countries with significant consumer and small business usage, the vulnerability could be exploited to target home offices, remote workers, or small enterprises, which are often less protected than large corporate networks. This could facilitate espionage, data theft, or disruption of network services, especially in sectors with sensitive data or critical infrastructure connections.

1. Immediate mitigation should include disabling remote management interfaces on the Tenda RX2 Pro routers to prevent external access to the web management portal. 2. Network administrators should verify that Telnet is disabled by default and ensure it remains so; if Telnet is enabled, it should be disabled unless absolutely necessary. 3. Apply network segmentation to isolate routers from critical internal networks to limit potential lateral movement. 4. Monitor network traffic for unusual HTTP requests targeting /goform/telnet or unexpected Telnet connection attempts. 5. Change all default credentials on the router to strong, unique passwords to reduce the risk of post-exploitation access. 6. If possible, update the router firmware to a patched version once available from the vendor; in the absence of a patch, consider replacing vulnerable devices with more secure alternatives. 7. Implement intrusion detection/prevention systems (IDS/IPS) rules to detect and block exploitation attempts targeting this vulnerability. 8. Educate users and administrators about the risks of exposing management interfaces and the importance of secure configuration practices.