2.6 Bind Mount the /var/tmp directory to /tmp

Information

The /var/tmp directory is normally a standalone directory in the /var file system. Binding /var/tmp to /tmp establishes an unbreakable link to /tmp that cannot be removed (even by the root user). It also allows /var/tmp to inherit the same mount options that /tmp owns, allowing /var/tmp to be protected in the same manner /tmp is protected. It will also prevent /var from filling up with temporary files as the contents of /var/tmp will actually reside in the file system containing /tmp. All programs that use /var/tmp and /tmp to read/write temporary files will always be written to the /tmp file system, preventing a user from running the /var file system out of space or trying to perform operations that have been blocked in the /tmp filesystem.

Solution

# mount --bind /tmp /var/tmp and edit the /etc/fstab file to contain the following line- /tmp /var/tmp none bind 0 0

See Also

https://workbench.cisecurity.org/files/85

Item Details

Category: CONFIGURATION MANAGEMENT

References: 800-53|CM-6, CSCv6|3.1, CSCv7|5.1

Plugin: Unix

Control ID: 703b5e4a6a46d30bab61eb85c98400d59aa3e055eddad947201b053b56e4f46e