The Intelligent Platform Management Interface (IPMI) implementation in the Blade Management Controller in Cisco Unified Computing System (UCS) allows remote attackers to enumerate valid usernames by observing IPMI interface responses, aka Bug ID CSCtg20761.
Improper Input Validation The product receives input or data, but it does
not validate or incorrectly validates that the input has the
properties that are required to process the data safely and
correctly.