Ssh20cisco125 Vulnerability Jun 2026

The SSH-2-Cisco-125 vulnerability is a buffer overflow vulnerability in the Secure Shell (SSH) implementation of Cisco IOS software. Specifically, it affects the SSHv2 (Secure Shell version 2) implementation on Cisco devices running IOS software versions 12.2(15)T and 12.3(2)T, and certain versions of IOS 12.0 and 12.1.

Isolating affected interfaces and applying strict traffic shaping. ssh20cisco125 vulnerability

A remote attacker could send a specific SSH packet that causes the device to crash or experience a memory access error. A remote attacker could send a specific SSH

Unauthenticated Remote Code Execution (RCE). its impact on Cisco devices

The ssh-20-cisco-125 vulnerability refers to a critical security weakness in the Secure Shell (SSH) protocol implementation on certain Cisco devices. This vulnerability has significant implications for network administrators and cybersecurity professionals, as it can allow unauthorized access to sensitive network devices. In this paper, we will examine the nature of the ssh-20-cisco-125 vulnerability, its impact on Cisco devices, and provide recommendations for mitigation and remediation.

Once the private key is factored, the attacker can generate valid host keys and install a persistent backdoor (e.g., a rogue admin account) without triggering alarms, because the SSH host key remains unchanged.