: Certain vulnerabilities can be exploited to cause a DoS, making the network device or service unavailable.
Organizations using Cisco devices with SSH 1.25 can take several steps to mitigate vulnerabilities:
"Cisco SSH 1.25" represents a deprecated, insecure protocol implementation. If you are scanning a network and finding this version: cisco ssh 1.25 vulnerabilities
SSH 1.25 typically supports only legacy, weak ciphers like or older 3DES modes. It lacks support for modern, secure ciphers like AES-256-GCM or ChaCha20. This makes the traffic easier to decrypt if captured.
Apply strict ACLs to the VTY lines to ensure only trusted IP addresses can attempt an SSH connection. : Certain vulnerabilities can be exploited to cause
Multiple vulnerabilities have allowed unauthenticated attackers to cause a device to reload or crash by sending malformed SSH packets. A specific issue in IOS and IOS XE (CVE-2022-20920) could allow an attacker to trigger a reload by continuously sending specific requests.
Here is a guide regarding the vulnerabilities associated with this specific legacy version and how to mitigate them. It lacks support for modern, secure ciphers like
The vulnerability wasn't a bug. It was a backdoor baked into the firmware image at the factory. A debug tool the original developers called "Project 1.25" for internal diagnostics, never meant for production. But when Cisco compressed the final IOS build, the parser left the door open.