Secure temporary files in Linux

On a typical Linux system there will be at least two, if not more, directories or partitions meant to hold temporary files. There is always the /tmp directory, and often a /var/tmp directory as well. With newer Linux kernels, there can also be /dev/shm, which is mounted using the tmpfs filesystem.

One problem with directories meant to store temporary files is that they can often be targeted as places to store bots and rootkits that compromise the system. This is because in most cases, anyone (or any process) can write to these directories.

(more...)