Ensure auditd Collects Information on Exporting to Media (successful)
Ensures auditd has an active rule tagged export that records successful mount syscalls by ordinary users, so exporting data to external/removable media is traceable.
Checked against the resolved running state (e.g. sshd -T, sysctl, systemctl show), catches drop-ins and Includes a file read would miss. Caveat: runtime ≠ persistence; a value correct now may not survive a reboot.
Pavois asserts the effective configuration, the live, resolved state, not a file. File-based scanners (OVAL/SCAP, Lynis) miss Includes, drop-ins and runtime defaults; this check sees what is actually applied.
A mapping is a cross-reference to where each standard places this requirement, anchored and cross-validated, not a claim of equivalence. A passing check is evidence toward these references, how to read it.
Why this rule matters
Unauthorized exportation of data to external media can cause information leaks where classified data, personal data and intellectual property are lost. Creating an audit record each time a filesystem is mounted helps identify and guard against such loss and supports investigation of data-exfiltration attempts.
What Pavois checks
Pavois runs auditctl -l and checks for a loaded rule carrying the export key. Reading the live kernel ruleset beats parsing /etc/audit/rules.d/*.rules: a rule present in a file but not loaded gives false assurance. auditctl -l reflects only what the kernel enforces now.
describe command('auditctl -l') do
its('stdout') { should match(/(-k +|key=)export\b/) }
end
describe command("grep -rhwsE 'export' /etc/audit/rules.d/*.rules /etc/audit/audit.rules 2>/dev/null") do
its('stdout') { should match(/\S/) }
endHow to verify it is applied
Run auditctl -l | grep export. You should see syscall rules such as -a always,exit -F arch=b64 -S mount -F auid>=1000 -F auid!=unset -k export (and a b32 variant). Empty output means the rule is not loaded.
Inspect & investigate
Triggered events land in /var/log/audit/audit.log. Search with grep 'key="export"' /var/log/audit/audit.log. Currently mounted filesystems are visible via findmnt (prefer grep over ausearch -k export, which can wrongly report no matches).
Remediation
Pavois's harden plan uses the audit_ruleset resource to write the mount syscall rule into /etc/audit/rules.d/, then reloads auditd. Because the audit config may be immutable, a reboot is required to fully apply. Run pavois harden apply.
Pavois applies this with its own harden engine, the plan below, not a shell script:
| reboot_required | true |
|---|---|
| resource | audit_ruleset |
pavois harden plan localwhere the target is local, a user@host SSH alias, or a container , Docs
Impact & precautions
Without this rule, copying data onto removable media leaves no record, hampering exfiltration investigations. The rule is log-only and cannot block mounts, so it breaks nothing. Precautions: mount activity from automounters, container runtimes and desktop sessions can be frequent, size audit.log rotation and space_left_action so a full disk does not halt the host when auditd is set to halt.
Standards mapping
| Standard | Reference | Type | Version | Confidence |
|---|---|---|---|---|
| ANSSI BP-028 | R73 | direct | 2.0 | high |
| CIS | 10.2.1.7, 6.2.3.10, 6.3.3.19, 6.3.3.10 | direct | per OS, see the benchmark table | high |
| NIST | 3.1.7, AC-6(9), AU-12(c), AU-2(d), CM-6(a) | supporting | 800-53 Rev 5 · 800-171 Rev 2 (pinned) | medium |
| PCI DSS | 10.2.1.7 | supporting | 4.0.1 | medium |
Each reference is a cross-reference anchored in the upstream benchmark and cross-validated against the SCAP Security Guide and ansible-lockdown, not a claim of equivalence. Direct = a prescriptive, line-level requirement; supporting = an abstract control family (NIST) the check provides evidence toward. How to read a mapping.