RHEL-10-701080 - RHEL 10 must enable kernel parameters to enforce discretionary access control (DAC) on symlinks.

Information

By enabling the "fs.protected_symlinks" kernel parameter, symbolic links are permitted to be followed only when outside a sticky world-writable directory, or when the user identifier (UID) of the link and follower match, or when the directory owner matches the symlink's owner. Disallowing such symlinks helps mitigate vulnerabilities based on insecure file systems accessed by privileged programs, avoiding an exploitation vector exploiting unsafe use of open() or creat().

Satisfies: SRG-OS-000312-GPOS-00122, SRG-OS-000312-GPOS-00123, SRG-OS-000324-GPOS-00125

Solution

Configure RHEL 10 to enable DAC on symlinks with the following:

Create a drop-in if it does not already exist:

$ sudo vi /etc/sysctl.d/99-fs_protected_symlinks.conf

Add the following to the file:

fs.protected_symlinks = 1

Reload settings from all system configuration files with the following command:

$ sudo sysctl --system

Item Details

Audit Name: DISA Red Hat Enterprise Linux 10 STIG v1r1

Category: ACCESS CONTROL

Plugin: Unix

Control ID: 11a2c8ddc2fe86ff97bf41c65e2be6ddba7c9cf96971c0ca3f8d58de19a359be

Detections

Analytics

RHEL-10-701080 - RHEL 10 must enable kernel parameters to enforce discretionary access control (DAC) on symlinks.

Information

Solution

See Also

Item Details