Ssh-2.0-cisco-1.25 — Vulnerability

: Administrators with access can enable debug ssh on a Cisco device to view the exact exchange of identification strings during connection attempts, as seen in the official Cisco documentation:

(if SSHv1 is acceptable for your environment):

Upgrade the device firmware to a supported release and regenerate RSA keys.

: Cisco-1.25 alone does not confirm any specific CVE. It must be cross-referenced with show version output. ssh-2.0-cisco-1.25 vulnerability

To help tailor this information to your network, please let me know:

: The communication relies on the modern, cryptographically secure SSH Version 2 protocol.

The identification of Cisco-1.25 suggests the device is utilizing an older SSH implementation library. Below are the primary vulnerabilities associated with this specific banner. : Administrators with access can enable debug ssh

The appearance of this string in security reports usually indicates the device is running a version of Cisco software that has not yet been hardened against recent SSH exploits. There are two primary security concerns currently associated with this banner: 1. The Terrapin Attack (CVE-2023-48795)

Security research reports from April 2025 highlighted significant global exposure for devices identifying as "SSH-2.0-Cisco-1.25". Approximately 92,000 exposed instances found. Censys: Over 103,000 instances identified. FOFA: Up to 309,000 instances detected. Related Historical Vulnerabilities

: A Man-in-the-Middle (MitM) attacker can downgrade the connection's security by deleting specific protocol messages during the handshake without the client or server noticing. Cisco Bug ID : CSCwi61646 . 2. Unauthenticated Remote Code Execution (CVE-2025-32433) To help tailor this information to your network,

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One of the most critical vulnerabilities tied to this engine allows remote, unauthenticated attackers to bypass system authentication completely .

access-list 10 permit 192.168.1.0 0.0.0.255 line vty 0 4 access-class 10 in transport input ssh