Title

SLEM 5 must generate audit records for all account creations, modifications, disabling, and termination events that affect /etc/shadow. (Cat II impact)

Discussion

Once an attacker establishes initial access to a system, the attacker often attempts to create a persistent method of reestablishing access. One way to accomplish this is for the attacker to simply create a new account. Auditing account creation mitigates this risk. To address access requirements, SLEM 5 may be integrated with enterprise-level authentication/access/auditing mechanisms that meet or exceed access control policy requirements.

Check Content

Verify SLEM 5 generates an audit record when modifications occur to the "/etc/shadow" file with the following command: > sudo auditctl -l | grep -w '/etc/shadow' -w /etc/shadow -p wa -k account_mod If the command does not return a line that matches the example or the line is commented out, this is a finding. Notes: The "-k" allows for specifying an arbitrary identifier. The string following "-k" does not need to match the example output above.

Fix Text

Configure SLEM 5 to generate an audit record when all modifications to the "/etc/shadow" file occur. Add or modify the following line in the "/etc/audit/rules.d/audit.rules" file: -w /etc/shadow -p wa -k account_mod To reload the rules file, restart the audit daemon: > sudo systemctl restart auditd.service or issue the following command: > sudo augenrules --load

Additional Identifiers

Rule ID: SV-261452r996763_rule

Vulnerability ID: V-261452

Group Title: SRG-OS-000004-GPOS-00004

Expert Comments

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