Ssh-2.0-cisco-1.25 Vulnerability

While you cannot easily alter the core protocol string ( SSH-2.0-Cisco-1.25 ) without a software upgrade, you can disable standard hardware and software banners to prevent additional information leakage:

0 Helpful. Georg Pauwen. VIP Alumni. ‎02-16-2021 12:30 AM. Hello, I think the '1.25' part is the Cisco specific vendor version ID. Cisco Community

To help tailor this information to your network, please let me know: ssh-2.0-cisco-1.25 vulnerability

Security tools often alert on this banner because it helps attackers perform fingerprinting

If you have identified devices reporting ssh-2.0-cisco-1.25 , follow this prioritized action plan. While you cannot easily alter the core protocol

This is a "prefix truncation" attack where a man-in-the-middle (MitM) attacker can secretly remove parts of the encrypted handshake.

Crafting an SSH inbound request using an invalid or specifically malformed reverse-login username causes an unhandled memory exception inside the Cisco internal SSH state machine. The operating system crashes and forces a cold reboot. 3. Weak Cryptographic Cipher Suites ‎02-16-2021 12:30 AM

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.

: A prefix truncation weakness in the SSH protocol that could allow a man-in-the-middle attacker to downgrade the connection's security by deleting messages from the beginning of the secure channel. Erlang SSH Remote Code Execution (RCE)