Ubuntu 22.04 LTS must use cryptographic mechanisms to protect the integrity of audit tools.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-260586	UBTU-22-651030	SV-260586r991567_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
Canonical Ubuntu 22.04 LTS Security Technical Implementation Guide	2024-05-30

Details

Check Text ( C-64315r953569_chk )
Verify that Advanced Intrusion Detection Environment (AIDE) is properly configured to use cryptographic mechanisms to protect the integrity of audit tools by using the following command: $ grep -E '(\/sbin\/(audit\|au))' /etc/aide/aide.conf /sbin/auditctl p+i+n+u+g+s+b+acl+xattrs+sha512 /sbin/auditd p+i+n+u+g+s+b+acl+xattrs+sha512 /sbin/ausearch p+i+n+u+g+s+b+acl+xattrs+sha512 /sbin/aureport p+i+n+u+g+s+b+acl+xattrs+sha512 /sbin/autrace p+i+n+u+g+s+b+acl+xattrs+sha512 /sbin/audispd p+i+n+u+g+s+b+acl+xattrs+sha512 /sbin/augenrules p+i+n+u+g+s+b+acl+xattrs+sha512 If any of the seven lines do not appear as shown, are commented out, or are missing, this is a finding.

Check Text ( C-64315r953569_chk )

Verify that Advanced Intrusion Detection Environment (AIDE) is properly configured to use cryptographic mechanisms to protect the integrity of audit tools by using the following command:

$ grep -E '(\/sbin\/(audit|au))' /etc/aide/aide.conf
/sbin/auditctl p+i+n+u+g+s+b+acl+xattrs+sha512
/sbin/auditd p+i+n+u+g+s+b+acl+xattrs+sha512
/sbin/ausearch p+i+n+u+g+s+b+acl+xattrs+sha512
/sbin/aureport p+i+n+u+g+s+b+acl+xattrs+sha512
/sbin/autrace p+i+n+u+g+s+b+acl+xattrs+sha512
/sbin/audispd p+i+n+u+g+s+b+acl+xattrs+sha512
/sbin/augenrules p+i+n+u+g+s+b+acl+xattrs+sha512

If any of the seven lines do not appear as shown, are commented out, or are missing, this is a finding.

Fix Text (F-64223r953570_fix)
Configure AIDE to protect the integrity of audit tools: Add or modify the following lines in the "/etc/aide/aide.conf" file: # Audit Tools /sbin/auditctl p+i+n+u+g+s+b+acl+xattrs+sha512 /sbin/auditd p+i+n+u+g+s+b+acl+xattrs+sha512 /sbin/ausearch p+i+n+u+g+s+b+acl+xattrs+sha512 /sbin/aureport p+i+n+u+g+s+b+acl+xattrs+sha512 /sbin/autrace p+i+n+u+g+s+b+acl+xattrs+sha512 /sbin/audispd p+i+n+u+g+s+b+acl+xattrs+sha512 /sbin/augenrules p+i+n+u+g+s+b+acl+xattrs+sha512

Fix Text (F-64223r953570_fix)

Configure AIDE to protect the integrity of audit tools:

Add or modify the following lines in the "/etc/aide/aide.conf" file:

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