no ip ssh version 1
Older Cisco IOS releases (12.x, early 15.x) allowed administrators to generate RSA keys with the command:
: Specifies the target hardware running software ecosystems such as Cisco IOS, IOS XE, IOS XR, or NX-OS .
SSH-2-Cisco-125 is a specific implementation of the Secure Shell (SSH) protocol, a cryptographic network protocol used to securely access and manage network devices. The "125" in the name refers to a specific Cisco device model, which is vulnerable to this exploit. ssh20cisco125 vulnerability
! Enforce SSH Version 2.0 strictly ip ssh version 2 ! ! Enforce modern cryptographic primitives ip ssh ciphers aes256-gcm,aes128-gcm ip ssh mac hmac-sha2-512,hmac-sha2-256 ip ssh dh min size 4096 Use code with caution. 4. Lifecycle Incident Response & Lifecycle Validation
While there is no single official vulnerability titled exactly "ssh20cisco125," that string typically refers to a specific SSH banner SSH-2.0-Cisco-1.25
This article provides an analysis of the situation as of early 2026. For the most up-to-date information, please refer to the Cisco Security Advisory listed above. If you'd like, I can: no ip ssh version 1 Older Cisco IOS releases (12
: Some versions are susceptible to Cross-Site Scripting (XSS). You can find more information on these updates through Cisco .
The SSH-2-Cisco-125 vulnerability is a type of remote code execution (RCE) vulnerability, which allows an attacker to execute arbitrary code on a vulnerable device without authentication. This vulnerability exists due to a flawed implementation of the SSH protocol in the Cisco device's firmware.
The "ssh20cisco125" scenario is considered high-risk for several key reasons: weak ciphers (3DES
If you have questions about any of these vulnerabilities or need help evaluating your current security posture, please reach out.
: Refers to SSH Version 2.0 . While vastly superior to the cryptographically broken SSH v1, standard SSH v2 can still host outdated key exchange algorithms (Diffie-Hellman Group 1), weak ciphers (3DES, RC4), or vulnerable software daemons.