Unpatched Critical Flaw in Cisco Small Business Switches Allows Attackers to Bypass User Authentication

A critical vulnerability with Cisco Small Business Switches that allows an remote attacker to log to an affected device and to execute commands with admin privileages.

The vulnerability can be tracked as CVE-2018-15439, and exists with Cisco Small Business Switch SOHO that used to manage the small local area networks.

Following are the products affected by the vulnerability

• Cisco Small Business 200 Series Smart Switches
• CSB 300 Series Managed Switches
• CSB 500 Series Stackable Managed Switches
• Cisco 250 Series Smart Switches
• Cisco 350 Series Managed Switches
• Cisco 350X Series Stackable Managed Switches
• Cisco 550X Series Stackable Managed Switches

Cisco Small Business Switches which runs with the which runs with default configuration on the devices listed as vulnerable includes a default, privileged user account that is used for the initial login and cannot be removed from the system are vulnerable, reads Cisco advisory.

“If all user-configured privilege level 15 accounts are removed from the device configuration, an affected software release re-enables the default privileged user account without notifying administrators of the system.”

Workarounds

Cisco recommends administrators to add atleast one user account with level 15 privilege in the device configuration, so that default privileged account will be disabled.

Cisco not yet released any software updates to address this vulnerability.

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