used by many modern Cisco products. It allows unauthenticated attackers to execute arbitrary code by sending specific messages before authentication occurs. Würth Phoenix Terrapin Attack (CVE-2023-48795)
The string SSH-2.0-Cisco-1.25 SSH server banner typically seen when connecting to Cisco IOS or IOS-XE devices. This banner itself is a version string, not a specific vulnerability, but its presence indicates the device is running a version of the Cisco SSH implementation that may be susceptible to several known protocol-level and implementation-specific vulnerabilities. Devolutions Forum Key Vulnerabilities Associated with Cisco SSH ssh-2.0-cisco-1.25 vulnerability
: Recent reports in April 2025 highlight a critical RCE vulnerability in the Erlang-based SSH server used in some Cisco product lines. This is a "Perfect 10" severity flaw that allows unauthenticated code execution. Cisco Community How to Verify and Mitigate SSH Terrapin Prefix Truncation Weakness - Cisco Community used by many modern Cisco products