|Article Summary||Resolution steps for capacity overflow attack vulnerability on /var file system.|
|Alert Impact||Impacted - Apply RSA Remedy|
|Alert Impact Explanation||The /var/tmp directory contains temporary files written by programs. There are several known capacity overflow attacks for the /var file system.|
|Resolution||A capacity overflow attack on the /var file system can be mitigated by binding the /var/tmp directory to the /tmp directory. This ensures no user or programs can consume all of the space in the /var file system. |
The following steps can be taken to automatically bind /var/tmp to /tmp at system boot time.
If the grep command returns no output, or returns only lines that do not "bind" /var/tmp, continue with step 3 below.
If the grep command returns an error, or finds a line that "binds" /var/tmp, do not continue.
The cat command should show that the last line in /etc/fstab is now:
A reboot is required to perform the mount because there are many lock files and communication-related temporary files maintained in /var/tmp. Running an explicit mount command in a running system may lead to issues when a local Oracle database is in use.
Should this change need to be backed out, the original /etc/fstab file can be copied from the backup directory to its original location with the following command:
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