A vulnerability in the upgrade process of Cisco Spark Board could allow an authenticated, local attacker to install an unverified upgrade package, aka Signature Verification Bypass. The vulnerability is due to insufficient upgrade package validation. An attacker could exploit this vulnerability by providing the upgrade process with an upgrade package that the attacker controls. An exploit could allow the attacker to install custom firmware to the Spark Board. Cisco Bug IDs: CSCvf84502.