After upgrade, verify the new banner (which should be something like SSH-2.0-Cisco-2.0 or SSH-2.0-Cisco-1.99 ).
For many legacy and current Cisco enterprise devices, this exposes SSH-2.0-Cisco-1.25 . This tells an analyst two things: ssh-2.0-cisco-1.25 vulnerability
: There is no separate “SSH-2.0-Cisco-1.25” CVE . Treat this banner as a red flag indicating you should verify your device’s IOS version against historical Cisco SSH DoS vulnerabilities. If you need the exact fixed IOS version for your hardware, provide the full show version output. After upgrade, verify the new banner (which should
Immediately apply these commands to mitigate risks: ssh-2.0-cisco-1.25 vulnerability
: The module mishandles invalid or malformed RSA keys during the validation phase.
To determine if SSH-2.0-Cisco-1.25 indicates a vulnerable device: