Developed by Dr. Gaius Baltar, the Command Navigation Program (CNP) was a program utilized by the Colonial military forces of the 12 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 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.
The CNP was received by the Galactica, but the program was never loaded into primary memory (Mini-Series. Lieutenant Gaeta has the program deleted 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.