Ssh-2.0-cisco-1.25 — Vulnerability

The risk is that this banner transforms the device into an "easy target" for automated scanning. An attacker scanning random IP ranges does not need to guess what is behind the IP address; the SSH banner provides an immediate and accurate answer. This direct mapping allows malicious actors to build targeted lists of potential Cisco devices for subsequent exploitation attempts.

Attackers establish standard SSH tunnels and blast specific, non-standard traffic patterns to mismatch internal variables.

The identifier is a software version string returned by the SSH banner on many Cisco IOS-based devices. While not a specific vulnerability name itself, this version string is frequently associated with several critical security flaws that affect the SSH implementation in Cisco IOS and IOS XE software. Notable Vulnerabilities Associated with Cisco SSH ssh-2.0-cisco-1.25 vulnerability

Limit who can access the SSH management interface using Access Control Lists (ACLs) to ensure only authorized management workstations can connect to the device.

: The flaw exists in the initial message negotiation phase before a user ever submits a password or cryptographic key. The risk is that this banner transforms the

Attackers can downgrade the connection's overall security, disable extension negotiations (like public-key keystroke obfuscation), and exploit subtle flaws in standard block ciphers.

This is a classic vulnerability found in Cisco IOS versions that shipped with SSH-2.0-Cisco-1.25 . A crafted SSHv2 packet could cause the device to reload. The attack required only a single TCP connection and did not need authentication. An unauthenticated, remote attacker could crash a core router or switch, causing a network-wide outage. Attackers establish standard SSH tunnels and blast specific,

Legacy software often lacks robust, built-in rate limiting for SSH connections, making it easier for attackers to guess credentials.

The most severe threat impacting systems aligned with this software stack is a .