Ssh-2.0-cisco-1.25 Vulnerability

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.

: This is the internal version of the Cisco SSH software implementation. Cisco Community Why Scanners Flag This ssh-2.0-cisco-1.25 vulnerability

Network scanning tools like Nmap or Shodan frequently report banners such as SSH-2.0-Cisco-1.25 . Penetration testers and security analysts may mistakenly search for a “CVE-XXXX-XXXX” matching this exact string. This paper corrects that misconception and provides a practical framework for risk assessment. Modern SSH implementations include features like strict key

While "security by obscurity" isn't a primary defense, you can prevent casual scanning from identifying your exact version. On some platforms, you can customize or suppress parts of the SSH banner via the banner command, though the protocol-level version string (Cisco-1.25) is often hard-coded into the stack. Summary Table Vulnerability Mitigation Security Downgrade Disable ChaCha20-Poly1305 and CBC ciphers. RCE (CVE-2025-32433) Full System Takeover Immediate software update/patching. Weak KEX/Ciphers Data Decryption Update ip ssh settings to use SHA-2 and CTR. Cisco Community Why Scanners Flag This Network scanning

Under precise conditions, the system bypasses user verification, logging the unauthorized actor directly into Virtual Teletype (VTY) administrative line interfaces. Summary Table: Vulnerability Matrix for Cisco-1.25 Devices