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Ssh20cisco125 Vulnerability Exclusive New! Online

This flaw fundamentally breaks the security model of public-key cryptography on affected devices. It allows a remote, unauthenticated attacker to log in to a Cisco Secure Firewall ASA device by bypassing the requirement for a private SSH key.

The vulnerability exists because of a weakness in the way the SSH server handles authentication on affected devices. When an attacker attempts to authenticate with a device using SSH, they can potentially bypass authentication and gain access to the device. ssh20cisco125 vulnerability exclusive

Disable vulnerable KEX algorithms:

Introduction

Why "Exclusive"?

The term exclusive in the keyword implies that this vulnerability is not yet for sale on exploit marketplaces like Zerodium or Exploit.in. Instead, it’s being used in targeted attacks against energy sector Cisco routers (e.g., Cisco 2900 series, ISR 4000) and industrial switches (IE-3000). A single threat actor, tracked as UNC5129 by Mandiant, has allegedly deployed implants via SSH20CISCO125 since Q4 2024. This flaw fundamentally breaks the security model of

This maximum-severity flaw (CVSS 10.0) affects Cisco Unified Communications Manager (Unified CM). SSH v2 enabled on the Cisco device (default

If you want, I can:

2. Technical Deep Dive: How the Exploit Works

Preconditions for Exploitation

  1. SSH v2 enabled on the Cisco device (default on most IOS images post-12.2).
  2. One of the vulnerable KEX algorithms enabled: diffie-hellman-group-exchange-sha256 or diffie-hellman-group14-sha1.
  3. No control plane protection (CoPP) or ACLs filtering SSH source addresses.