A vulnerability in the Secure Shell (SSH) authentication process of Cisco Small Business Switches software could allow an attacker to bypass client-side certificate authentication and revert to password authentication. The vulnerability exists because OpenSSH mishandles the authentication process. An attacker could exploit this vulnerability by attempting to connect to the device via SSH. A successful exploit could allow the attacker to access the configuration as an administrative user if the default credentials are not changed. There are no workarounds available; however, if client-side certificate authentication is enabled, disable it and use strong password authentication. Client-side certificate authentication is disabled by default.

A vulnerability in the Cisco Small Business Switches software could allow an unauthenticated, remote attacker to bypass the user authentication mechanism of an affected device. The vulnerability exists because under specific circumstances, the affected software enables a privileged user account without notifying administrators of the system. An attacker could exploit this vulnerability by using this account to log in to an affected device and execute commands with full admin rights. Cisco has not released software updates that address this vulnerability. This advisory will be updated with fixed software information once fixed software becomes available. There is a workaround to address this vulnerability.

A vulnerability in the Secure Shell (SSH) subsystem of Cisco Small Business Managed Switches software could allow an authenticated, remote attacker to cause a reload of the affected switch, resulting in a denial of service (DoS) condition. The vulnerability is due to improper processing of SSH connections. An attacker could exploit this vulnerability by logging in to an affected switch via SSH and sending a malicious SSH message. This vulnerability affects the following Cisco products when SSH is enabled: Small Business 300 Series Managed Switches, Small Business 500 Series Stackable Managed Switches, 350 Series Managed Switches, 350X Series Stackable Managed Switches, 550X Series Stackable Managed Switches, ESW2 Series Advanced Switches. Cisco Bug IDs: CSCvb48377.