RHEL-08-040137 - The RHEL 8 fapolicy module must be configured to employ a deny-all, permit-by-exception policy to allow the execution of authorized software programs.

Information

The organization must identify authorized software programs and permit execution of authorized software. The process used to identify software programs that are authorized to execute on organizational information systems is commonly referred to as whitelisting.

Utilizing a whitelist provides a configuration management method for allowing the execution of only authorized software. Using only authorized software decreases risk by limiting the number of potential vulnerabilities. Verification of whitelisted software occurs prior to execution or at system startup.

User home directories/folders may contain information of a sensitive nature. Non-privileged users should coordinate any sharing of information with an SA through shared resources.

RHEL 8 ships with many optional packages. One such package is a file access policy daemon called 'fapolicyd'. 'fapolicyd' is a userspace daemon that determines access rights to files based on attributes of the process and file. It can be used to either blacklist or whitelist processes or file access.

Proceed with caution with enforcing the use of this daemon. Improper configuration may render the system non-functional. The 'fapolicyd' API is not namespace aware and can cause issues when launching or running containers.

Satisfies: SRG-OS-000368-GPOS-00154, SRG-OS-000370-GPOS-00155, SRG-OS-000480-GPOS-00232

Solution

Configure RHEL 8 to employ a deny-all, permit-by-exception application whitelisting policy with 'fapolicyd'.

With the 'fapolicyd' installed and enabled, configure the daemon to function in permissive mode until the whitelist is built correctly to avoid system lockout. Do this by editing the '/etc/fapolicyd/fapolicyd.conf' file with the following line:

permissive = 1

For RHEL 8.4 systems and older:
Build the whitelist in the '/etc/fapolicyd/fapolicyd.rules' file ensuring the last rule is 'deny perm=any all : all'.

For RHEL 8.5 systems and newer:
Build the whitelist in a file within the '/etc/fapolicyd/rules.d' directory ensuring the last rule is 'deny perm=any all : all'.

Once it is determined the whitelist is built correctly, set the fapolicyd to enforcing mode by editing the 'permissive' line in the /etc/fapolicyd/fapolicyd.conf file.

permissive = 0

See Also

https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_RHEL_8_V2R1_STIG.zip

Item Details

Category: CONFIGURATION MANAGEMENT

References: 800-53|CM-7(2), CAT|II, CCI|CCI-001764, Rule-ID|SV-244546r1017349_rule, STIG-ID|RHEL-08-040137, Vuln-ID|V-244546

Plugin: Unix

Control ID: b5bae451aeb31ad02add4343c603031cf4ac2ec51960fadfe1a6701dcb7e5451