Thread: Secure temp on cPanel servers

The first step is to check if /tmp is already secure. Some datacenters do not create a /tmp partition while others do.
-----command-----
df -h |grep tmp
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If that displays nothing then go below to create a tmp partition. If you do have a tmp partition you need to see if it mounted with noexec.
-----command-----
cat /etc/fstab |grep tmp
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If there is a line that includes /tmp and noexec then it is already mounted as non-executable. If not follow the instructions below to create one without having to physically format your disk. Idealy you would make a real partition when the disk was originally formated, that being said I have not had any trouble create a /tmp partition using the following method.

Create a 190Mb partition
-----command-----
cd /dev/; dd if=/dev/zero of=tmpMnt bs=1024 count=200000
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Format the partion
-----command-----
mke2fs /dev/tmpMnt
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When it asks about not being a block special device press Y


Make a backup of the old data
-----command-----
cp -Rp /tmp /tmp_backup
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Mount the temp filesystem
-----command-----
mount -o loop,noexec,nosuid,rw /dev/tmpMnt /tmp
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Set the permissions
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chmod 0777 /tmp
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Copy the old files back
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cp -Rp /tmp_backup/* /tmp/
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Once you do that go ahead and restart mysql and make sure it works ok. We do this because mysql places the mysql.sock in /tmp which neeeds to be moved. If not it migth have trouble starting. If it does you can add this line to the bottom of the /etc/fstab to automatically have it mounted:

Open the file in pico:
-----command-----
pico -w /etc/fstab
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Now add this single line at the bottom:

/dev/tmpMnt /tmp ext2 loop,noexec,nosuid,rw 0 0

While we are at it we are going to secure /dev/shm. Look for the mount line for /dev/shm and change it to the following:
none /dev/shm tmpfs noexec,nosuid 0 0

Umount and remount /dev/shm for the changes to take effect.
-----command-----
umount /dev/shm
mount /dev/shm
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Next delete the old /var/tmp and create a link to /tmp
-----command-----
rm -rf /var/tmp/
ln -s /tmp/ /var/
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If everything still works fine you can go ahead and delete the /tmp_backup directory.
-----command-----
rm -rf /tmp_backup
-----command-----

Or you can just run this

/scripts/securetmp

cPanel - The Leading Control Panel

Though you're method will always work, where as the CP script doesn't