CP Plus CP-VNR-3104 Timing Attack Vulnerability Allowing Private Key Extraction and Man-in-the-Middle Access

A vulnerability exists in the CP Plus CP-VNR-3104 model, specifically in the firmware version B3223P22C02424. This issue allows attackers to exploit a timing discrepancy in the device's encryption process, particularly within the Elliptic Curve mathematics library. By observing the timing of multiple deterministic ECDSA signature generations, an attacker can extract the second RSA private key. This key extraction could lead to unauthorized access to sensitive information or facilitate a man-in-the-middle attack.

Impact

Exploitation of this vulnerability allows for the extraction of the RSA private key, which could be used to access sensitive data or impersonate the device in a man-in-the-middle attack.

Reproduction

The vulnerability can be reproduced by uploading a firmware update that has been modified to include a malicious payload. This can be done using the device's firmware update mechanism, which will decrypt the uploaded file and execute it as part of the update process. The extracted private key can then be used to access sensitive data or conduct a man-in-the-middle attack.