CVE-2025-13399 identifies a cryptographic weakness in the TP-Link VX800v v1.0 device, specifically in its web interface application layer encryption. The root cause is insufficient entropy used during AES key generation, resulting in weak encryption keys that can be brute forced by an attacker with network adjacency. The vulnerability does not require authentication or user interaction, lowering the barrier for exploitation. An attacker positioned on the same local network or within adjacent network segments can intercept encrypted traffic and perform brute force attacks against the AES key to decrypt sensitive data. The weakness impacts confidentiality by exposing transmitted data, integrity by allowing potential manipulation of decrypted content, and availability if the attacker disrupts communications. The CVSS 4.0 score of 7.7 reflects a high severity, with attack vector classified as adjacent network (AV:A), high attack complexity (AC:H), and no privileges or user interaction required. No patches are currently available, and no known exploits have been reported in the wild. The vulnerability is classified under CWE-331 (Insufficient Entropy), highlighting poor cryptographic key generation practices. This flaw is critical for environments relying on VX800v devices for secure communications, especially where sensitive or critical data is transmitted over local networks.

For European organizations, this vulnerability could lead to significant data breaches if VX800v devices are deployed in sensitive network segments. Confidentiality is at risk as attackers can decrypt intercepted traffic, potentially exposing personal data, intellectual property, or operational information. Integrity could be compromised if attackers manipulate decrypted data before re-encryption or injection. Availability might be affected if attackers disrupt communications or leverage decrypted information to launch further attacks. Sectors such as finance, healthcare, government, and critical infrastructure using these devices for secure local communications face heightened risks. The requirement for network adjacency limits remote exploitation but does not eliminate risk in environments with shared or poorly segmented networks. The lack of authentication requirement increases the threat from insider attackers or compromised devices within the local network. Without vendor patches, organizations must rely on network controls and monitoring to mitigate risk.

1. Immediately segment networks to isolate VX800v devices from untrusted or less secure network segments, minimizing attacker adjacency. 2. Employ network monitoring and intrusion detection systems to detect unusual traffic patterns or brute force attempts targeting the device. 3. Replace VX800v v1.0 devices with updated models or alternative products that do not suffer from weak encryption key generation. 4. If replacement is not feasible, implement VPN tunnels or additional encryption layers external to the device to protect sensitive data in transit. 5. Restrict physical and logical access to the local network segments hosting these devices to trusted personnel only. 6. Engage with TP-Link for updates or patches and apply them promptly once available. 7. Conduct regular security audits and penetration tests focusing on local network vulnerabilities and cryptographic implementations. 8. Educate network administrators about the risks of weak entropy in cryptographic systems and the importance of robust key generation.