The noexec mount option specifies that the filesystem cannot contain executable binaries. Rationale: Setting this option on a file system prevents users from executing programs from the removable media. This deters users from being able to introduce potentially malicious software on the system.
Edit the /etc/fstab file and add noexec to the fourth field (mounting options) of all removable media partitions. Look for entries that have mount points that contain words such as floppy or cdrom. See the fstab(5) manual page for more information.