Ssh-2.0-cisco-1.25 Vulnerability -

Leaving older SSH versions exposed allows attackers to fingerprint your hardware and launch targeted exploits. The Cisco-1.25 software branch is associated with several historical vulnerabilities, depending on the underlying IOS version:

This article provides a deep dive into the risks associated with devices reporting SSH-2.0-Cisco-1.25 , specifically focusing on the most relevant vulnerabilities, and outlines necessary mitigation steps. 1. What is the SSH-2.0-Cisco-1.25 Identifier?

The banner SSH-2.0-Cisco-1.25 is a historical marker that points to a legacy software stack that has been the source of several significant vulnerabilities. Understanding these issues is crucial for anyone maintaining older Cisco infrastructure.

The string SSH-2.0-Cisco-1.25 SSH server banner typically seen when connecting to Cisco IOS or IOS-XE devices. This banner itself is a version string, not a specific vulnerability, but its presence indicates the device is running a version of the Cisco SSH implementation that may be susceptible to several known protocol-level and implementation-specific vulnerabilities. Devolutions Forum Key Vulnerabilities Associated with Cisco SSH ssh-2.0-cisco-1.25 vulnerability

However, "Cisco-1.25" is found across many different IOS versions. Depending on which IOS version you are running, your device might be vulnerable to several real, documented threats: SSH Terrapin Prefix Truncation Weakness - Cisco Community

ip access-list standard MGMT_HOSTS permit 10.100.50.0 0.0.0.255 ! line vty 0 4 access-class MGMT_HOSTS in transport input ssh Use code with caution. Step 3: Hardening Cryptographic Ciphers

If your device reports this version string, it may be affected by the following vulnerabilities depending on the specific software release (IOS/IOS-XE): RSA-Based Authentication Bypass (CVE-2015-6280) Leaving older SSH versions exposed allows attackers to

When a client initiates an SSH connection to a device, the two systems exchange software version strings. This process is called banner grabbing. The string breaks down as follows: : The device uses SSH version 2.0.

: A vulnerability in the SSH state machine of Cisco IOS and IOS-XE Software could allow an authenticated, remote attacker to cause the device to reload by sending a specific traffic pattern, leading to a Denial of Service (DoS). Terrapin Attack (CVE-2023-48795)

An attacker can send specific protocol messages before authenticating, exploiting a memory or logic error in how the SSH server handles early communication. What is the SSH-2

Attackers can downgrade the connection's overall security, disable extension negotiations (like public-key keystroke obfuscation), and exploit subtle flaws in standard block ciphers.

A: Yes, via ip ssh version and ip ssh server algorithm commands, plus changing the login banner. But this is "security by obscurity." A determined attacker will still probe for vulnerabilities.

Look for SSH-2.0-Cisco-1.25 and then check supported KEX/algorithms. Older banners often still allow diffie-hellman-group1-sha1 (weak).