1.1.23 Disable Automounting

Information

autofs allows automatic mounting of devices, typically including CD/DVDs and USB drives.

Notes:

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Additional methods of disabling a service exist. Consult your distribution documentation for appropriate methods.

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This control should align with the tolerance of the use of portable drives and optical media in the organization.

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On a server requiring an admin to manually mount media can be part of defense-in-depth to reduce the risk of unapproved software or information being introduced or proprietary software or information being exfiltrated.

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If admins commonly use flash drives and Server access has sufficient physical controls, requiring manual mounting may not increase security.

With automounting enabled anyone with physical access could attach a USB drive or disc and have its contents available in system even if they lacked permissions to mount it themselves.

Solution

Run the following command to mask autofs :

# systemctl --now mask autofs

Impact:

The use of portable hard drives is very common for workstation users. If your organization allows the use of portable storage or media on workstations and physical access controls to workstations is considered adequate there is little value add in turning off automounting.

See Also

https://workbench.cisecurity.org/benchmarks/8498