The identifier is not a standard CVE (Common Vulnerabilities and Exposures) number, but rather a specific SSH banner string observed on some older Cisco devices.
Modern SSH implementations include features like strict key checking, modern key exchange algorithms (like Curve25519), and robust defenses against timing attacks. A device running version 1.25 lacks these modern safeguards, making it a soft target for Man-in-the-Middle (MitM) attacks. ssh-2.0-cisco-1.25 vulnerability