CVE-2023-20186: SSH20Cisco125 Vulnerability - A Critical Security Threat
- Immediate Action: Review your current SSH implementations and versions. Check with your vendors for any known vulnerabilities and apply patches immediately.
- Long-term Strategy: Regularly review and update your cybersecurity policies and procedures to reflect the evolving threat landscape.
Recommended Action Plan (priority)
- Inventory devices showing "SSH-2.0-Cisco-1.25" banner.
- Restrict SSH reachability to management IP ranges (ACLs/firewall).
- Apply control-plane policing / rate limits.
- Schedule IOS upgrades to fixed releases.
- Monitor logs and network telemetry for SSH anomalies.
Send malformed KEXINIT
kexinit = b"\x14" # SSH_MSG_KEXINIT
kexinit += b"\x00" * 16 # cookie (zeroed)
kexinit += b"\x00" * 40 # supported algorithms (dummy)