TOSS must use cryptographic mechanisms to protect the integrity of audit tools.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-253023	TOSS-04-030780	SV-253023r824741_rule		Medium

Description
Protecting the integrity of the tools used for auditing purposes is a critical step toward ensuring the integrity of audit information. Audit information includes all information (e.g., audit records, audit settings, and audit reports) needed to successfully audit information system activity. Audit tools include, but are not limited to, vendor-provided and open-source audit tools needed to successfully view and manipulate audit information system activity and records. Audit tools include custom queries and report generators. It is not uncommon for attackers to replace the audit tools or inject code into the existing tools with the purpose of providing the capability to hide or erase system activity from the audit logs. To address this risk, audit tools must be cryptographically signed in order to provide the capability to identify when the audit tools have been modified, manipulated, or replaced. An example is a checksum hash of the file or files.

Description

Protecting the integrity of the tools used for auditing purposes is a critical step toward ensuring the integrity of audit information. Audit information includes all information (e.g., audit records, audit settings, and audit reports) needed to successfully audit information system activity. Audit tools include, but are not limited to, vendor-provided and open-source audit tools needed to successfully view and manipulate audit information system activity and records. Audit tools include custom queries and report generators. It is not uncommon for attackers to replace the audit tools or inject code into the existing tools with the purpose of providing the capability to hide or erase system activity from the audit logs. To address this risk, audit tools must be cryptographically signed in order to provide the capability to identify when the audit tools have been modified, manipulated, or replaced. An example is a checksum hash of the file or files.

STIG	Date
Tri-Lab Operating System Stack (TOSS) 4 Security Technical Implementation Guide	2022-08-29

Details

Check Text ( C-56476r824739_chk )
Verify that Advanced Intrusion Detection Environment (AIDE) is properly configured to use cryptographic mechanisms to protect the integrity of audit tools. If AIDE is not installed, ask the System Administrator how file integrity checks are performed on the system. Check the selection lines to ensure AIDE is configured to add/check with the following command: $ sudo egrep '(\/usr\/sbin\/(audit\|au\|rsys))' /etc/aide.conf /usr/sbin/auditctl p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/auditd p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/ausearch p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/aureport p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/autrace p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/rsyslogd p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/augenrules p+i+n+u+g+s+b+acl+xattrs+sha512 If any of the audit tools listed above do not have an appropriate selection line, ask the system administrator to indicate what cryptographic mechanisms are being used to protect the integrity of the audit tools. If there is no evidence of integrity protection, this is a finding. If any of the audit tools are not installed on the system, the corresponding AIDE rule is not applicable.

Check Text ( C-56476r824739_chk )

Verify that Advanced Intrusion Detection Environment (AIDE) is properly configured to use cryptographic mechanisms to protect the integrity of audit tools.

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

Check the selection lines to ensure AIDE is configured to add/check with the following command:

$ sudo egrep '(\/usr\/sbin\/(audit|au|rsys))' /etc/aide.conf

/usr/sbin/auditctl p+i+n+u+g+s+b+acl+xattrs+sha512
/usr/sbin/auditd p+i+n+u+g+s+b+acl+xattrs+sha512
/usr/sbin/ausearch p+i+n+u+g+s+b+acl+xattrs+sha512
/usr/sbin/aureport p+i+n+u+g+s+b+acl+xattrs+sha512
/usr/sbin/autrace p+i+n+u+g+s+b+acl+xattrs+sha512
/usr/sbin/rsyslogd p+i+n+u+g+s+b+acl+xattrs+sha512
/usr/sbin/augenrules p+i+n+u+g+s+b+acl+xattrs+sha512

If any of the audit tools listed above do not have an appropriate selection line, ask the system administrator to indicate what cryptographic mechanisms are being used to protect the integrity of the audit tools. If there is no evidence of integrity protection, this is a finding.

If any of the audit tools are not installed on the system, the corresponding AIDE rule is not applicable.

Fix Text (F-56426r824740_fix)
Add or update the following lines to "/etc/aide.conf", to protect the integrity of the audit tools. # Audit Tools /usr/sbin/auditctl p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/auditd p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/ausearch p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/aureport p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/autrace p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/rsyslogd p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/augenrules p+i+n+u+g+s+b+acl+xattrs+sha512

Fix Text (F-56426r824740_fix)

Add or update the following lines to "/etc/aide.conf", to protect the integrity of the audit tools.

# Audit Tools
/usr/sbin/auditctl p+i+n+u+g+s+b+acl+xattrs+sha512
/usr/sbin/auditd p+i+n+u+g+s+b+acl+xattrs+sha512
/usr/sbin/ausearch p+i+n+u+g+s+b+acl+xattrs+sha512
/usr/sbin/aureport p+i+n+u+g+s+b+acl+xattrs+sha512
/usr/sbin/autrace p+i+n+u+g+s+b+acl+xattrs+sha512
/usr/sbin/rsyslogd p+i+n+u+g+s+b+acl+xattrs+sha512
/usr/sbin/augenrules p+i+n+u+g+s+b+acl+xattrs+sha512