Ssh-2.0-cisco-1.25 Vulnerability !!top!! Jun 2026

The SSH-2.0-Cisco-1.25 vulnerability is a weakness in the Cisco SSH implementation that allows an attacker to exploit the protocol's authentication mechanism. Specifically, the vulnerability occurs when an attacker sends a specially crafted SSH packet to a device running the vulnerable software. This packet can cause the device to crash or, in some cases, allow the attacker to gain unauthorized access to the device.

Indicates support for the Secure Shell version 2 protocol. Cisco: Identifies the vendor implementation. ssh-2.0-cisco-1.25 vulnerability

To protect devices running these SSH versions, administrators should follow these guidelines: The SSH-2

In 2019, a regional water utility in the Midwestern US (name redacted) was flagged in a Shodan audit. Their SCADA management network had four Cisco 2811 routers, all reporting SSH-2.0-Cisco-1.25 . An external pen test revealed: Indicates support for the Secure Shell version 2 protocol

The ssh-2.0-cisco-1.25 keyword is not a singular, patchable vulnerability like a buffer overflow. Instead, it is a —a loud signal that your network contains a fossilized device running turn-of-the-century software.

Modern penetration testing frameworks (Metasploit, Nuclei) check for this banner. For example, Nuclei’s ssh-version template will flag it as high risk . The next step in an automated attack chain is to try known IOS exploits from that era, such as: