Information
This takes allowlist aka whitelisting to the next level - where all software, libraries and scripts that are not in the trusted signature database (TSD) in /etc/security/tsd/tsd.dat are blocked.
Trusted Execution (TE) provides an additional layer of access controls to processes on top of the base Discretionary Access Controls. Monitoring how processes access system resources can improve awareness of system integrity.
Solution
- Execute one of the following commands:
trustchk -p stop_untrustd=on stop_on_chkfail=on te=on
or
trustchk -p stop_untrustd=trojan stop_on_chkfail=on te=on
Impact:
The step is reversible. By returning the TE policies STOP_UNTRUSTD and STOP_ON_CHKFAIL back to OFF the system will be returned to the Level 1 Profile.
An intermediate Level would be to set STOP_UNTRUSTD to TROJAN rather than ON (Level 2) or OFF (Level 1).
TROJAN Stops the loading of files that do not belong to the TSD and have one of the following security settings:
* Have suid/sgid bit set
* Linked to a file in the TSD
* Have entry in the privcmds Database
* Be linked to a file in the privcmds database