Vulnerability Discussion

Without verification of the security functions, security functions may not operate correctly, and the failure may go unnoticed. Security function is defined as the hardware, software, and/or firmware of the information system responsible for enforcing the system security policy and supporting the isolation of code and data on which the protection is based. Security functionality includes, but is not limited to, establishing system accounts, configuring access authorizations (i.e., permissions, privileges), setting events to be audited, and setting intrusion detection parameters.

This requirement applies to the OL 8 operating system performing security function verification/testing and/or systems and environments that require this functionality.

Check

Verify that Advanced Intrusion Detection Environment (AIDE) is installed and verifies the correct operation of all security functions.

Check that the AIDE package is installed with the following command:
$ sudo rpm -q aide

aide-0.16-14.el8_5.1.x86_64

If AIDE is not installed, ask the System Administrator how file integrity checks are performed on the system.

If there is no application installed to perform integrity checks, this is a finding.

If AIDE is installed, check if it has been initialized with the following command:
$ sudo /usr/sbin/aide --check

If the output is "Couldn't open file /var/lib/aide/aide.db.gz for reading", this is a finding.

Fix

Install AIDE, initialize it, and perform a manual check.

Install AIDE:
$ sudo yum install aide

Initialize it:
$ sudo /usr/sbin/aide --init

Example output:
Number of entries: 48623

---------------------------------------------------
The attributes of the (uncompressed) database(s):
---------------------------------------------------

/var/lib/aide/aide.db.new.gz
SHA1 : LTAVQ8tFJthsrf4m9gfRpnf1vyc=
SHA256 : NJ9+uzRQKSwmLQ8A6IpKNvYjVKGbhSjt
BeJBVcmOVrI=
SHA512 : 7d8I/F6A1b07E4ZuGeilZjefRgJJ/F20
eC2xoag1OsOVpctt3Mi7Jjjf3vFW4xoY
5mdS6/ImQpm0xtlTLOPeQQ==

End timestamp: 2022-10-20 10:50:52 -0700 (run time: 0m 46s)

The new database will need to be renamed to be read by AIDE:
$ sudo mv /var/lib/aide/aide.db.new.gz /var/lib/aide/aide.db.gz

Perform a manual check:
$ sudo /usr/sbin/aide --check

Example output:
Start timestamp: 2022-10-20 11:03:16 -0700 (AIDE 0.16)
AIDE found differences between database and filesystem!!
...

Done.