The string "SSH-2.0-Cisco-1.25" is a version identifier frequently returned by the Secure Shell (SSH) server on Cisco IOS and IOS XE devices during a protocol handshake. While this specific string describes the Cisco implementation of the SSH-2.0 protocol rather than a single vulnerability, devices reporting this version have recently been linked to a maximum-severity flaw (CVSS 10.0) in the underlying Erlang/OTP SSH server implementation. The Critical Erlang/OTP SSH Vulnerability
Q: Is ssh-2.0-cisco-1.25 a virus or malware?
A: No. It is a version banner. However, it indicates the device is likely missing security patches, making it a prime target for malware or ransomware. ssh-2.0-cisco-1.25 vulnerability
Mechanism: The flaw exists in the handling of SSH protocol messages during the authentication phase. An unauthenticated, remote attacker can send specific connection protocol messages before authentication is completed. The string "SSH-2
If your scanner has flagged this banner, follow these steps to mitigate the risk: Step 1: Update Your IOS/IOS XE Software Mechanism: The flaw exists in the handling of
The vulnerability is caused by a buffer overflow condition in the Cisco SSH implementation. When a client attempts to authenticate using keyboard-interactive authentication, the server does not properly validate the length of the authentication request. This allows an attacker to send a specially crafted request that overflows the buffer, potentially allowing the attacker to execute arbitrary code on the server.
Operational trade-offs
Final note: There is no separate “SSH-2.0-Cisco-1.25” CVE. Treat this banner as a red flag indicating you should verify your device’s IOS version against historical Cisco SSH DoS vulnerabilities. If you need the exact fixed IOS version for your hardware, provide the full show version output.