FlatNuke 2.5.5 and possibly earlier versions allows remote attackers to obtain sensitive information via (1) a null byte or (2) an MS-DOS device name such as AUX, CON, PRN, COM1, or LPT1 in the mod parameter.
https://euvd.enisa.europa.eu/vulnerability/EUVD-2005-2539
http://www.rgod.altervista.org/flatnuke.html