Developed by Dr. Gaius Baltar, the Command Navigation Program (CNP) was a program utilized by the Colonial military forces of the Twelve Colonies. Installed in Vipers, Raptors and Battlestars, it was a contrivance that was more than two years in the making.
Unbeknownst to Baltar, a version of the Humano-Cylon agent Number Six, who aided in programming the CNP, also programmed backdoors into the program so that the Cylon attack force could infiltrate and destroy any offending ships without so much as a retaliatory response. Ships with the CNP that received a command from an attacking Cylon ship would see their power, defense networks, and computers shut down as if a switch were flipped.
The CNP was disbursed as with all Colonial software updates via the Colonial Defense Mainframe, where Six had unrestricted access on Baltar's authorization.
The CNP was received by the Galactica, but the program was never loaded into primary memory (Mini-Series). Lieutenant Felix Gaeta has the program code purged from the mainframe on Baltar's suggestion, and the program was also deleted from the flight systems of any of the Galactica's surviving Mark VII Vipers and Raptors that had previously received the upgrade.