The Photon operating system must enable hardlink access control protection in the kernel.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-258903	PHTN-40-000244	SV-258903r933770_rule		Medium

Description
By enabling the fs.protected_hardlinks kernel parameter, users can no longer create soft or hard links to files they do not own. Disallowing such hardlinks mitigate vulnerabilities based on insecure file system accessed by privileged programs, avoiding an exploitation vector exploiting unsafe use of open() or creat().

STIG	Date
VMware vSphere 8.0 vCenter Appliance Photon OS 4.0 Security Technical Implementation Guide	2023-10-29

Details

Check Text ( C-62643r933768_chk )
At the command line, run the following command to verify hardlink protection is enabled: # /sbin/sysctl fs.protected_hardlinks Example result: fs.protected_hardlinks = 1 If the "fs.protected_hardlinks" kernel parameter is not set to "1", this is a finding.

Fix Text (F-62552r933769_fix)
Navigate to and open: /etc/sysctl.d/zz-stig-hardening.conf Add or update the following line: fs.protected_hardlinks = 1 At the command line, run the following command to load the new configuration: # /sbin/sysctl --load /etc/sysctl.d/zz-stig-hardening.conf Note: If the file zz-stig-hardening.conf does not exist, it must be created.