What is computer spillage?

Answer 1

Spillage is when information classified at a higher level is introduced to a computer classified at a lower level. In practice it includes any instance where such information MAY have been introduced. As an example: a laptop computer that is normally connected to a lower classification level network is connected to a higher level network in an attempt to check email. It is unknown if any higher classification data was transferred during the connection. The incident is treated as potential spillage and the hard drive of the computer is now considered classified.

Answer 2

Security incident that occurs whenever classified data is spilled either onto an unclassified IS or to an IS with a lower level of classification.