Title

Amazon Linux 2023 must prevent files with the setuid and setgid bit set from being executed on the /boot/efi directory. (Cat II impact)

Discussion

The "nosuid" mount option causes the system not to execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access.

Check Content

Verify Amazon Linux 2023 is configured so that the /boot/efi directory is mounted with the "nosuid" option with the following command: $ mount | grep '\s/boot/efi\s' /dev/sda1 on /boot/efi type vfat (rw,nosuid,relatime,fmask=0077,dmask=0077,codepage=437,iocharset=ascii,shortname=winnt,errors=remount-ro) If the /boot/efi file system does not have the "nosuid" option set, this is a finding.

Fix Text

Configure Amazon Linux 2023 so that the /boot/efi directory is mounted with the "nosuid" option. Modify "/etc/fstab" to use the "nosuid" option on the "/boot/efi" directory.

Additional Identifiers

Rule ID: SV-274178r1120522_rule

Vulnerability ID: V-274178

Group Title: SRG-OS-000368-GPOS-00154

Expert Comments

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