4.1.15 Ensure file deletion events by users are collected - 32 bit

Information

Monitor the use of system calls associated with the deletion or renaming of files and file attributes. This configuration statement sets up monitoring for the unlink (remove a file), unlinkat (remove a file attribute), rename (rename a file) and renameat (rename a file attribute) system calls and tags them with the identifier 'delete'.

Rationale:

Monitoring these calls from non-privileged users could provide a system administrator with evidence that inappropriate removal of files and file attributes associated with protected files is occurring. While this audit option will look at all events, system administrators will want to look for specific privileged files that are being deleted or altered.

Solution

For 32 bit systems Edit or create a file in the /etc/audit/rules.d/ directory ending in .rules
Example: vi /etc/audit/rules.d/audit.rules
and add the following lines:

-a always,exit -F arch=b32 -S unlink -S unlinkat -S rename -S renameat -F auid>=500 -F auid!=4294967295 -k delete

For 64 bit systems Edit or create a file in the /etc/audit/rules.d/ directory ending in .rules
Example: vi /etc/audit/rules.d/audit.rules
and add the following lines:

-a always,exit -F arch=b64 -S unlink -S unlinkat -S rename -S renameat -F auid>=500 -F auid!=4294967295 -k delete
-a always,exit -F arch=b32 -S unlink -S unlinkat -S rename -S renameat -F auid>=500 -F auid!=4294967295 -k delete




Notes:

At a minimum, configure the audit system to collect file deletion events for all users and root.

Reloading the auditd config to set active settings may require a system reboot.

This Benchmark recommendation maps to:

Red Hat Enterprise Linux 7 Security Technical Implementation Guide:

Version 2, Release: 3 Benchmark Date: 26 Apr 2019



Vul ID: V-72199

Rule ID: SV-86823r4_rule

STIG ID: RHEL-07-030880

Severity: CAT II



Vul ID: V-72201

Rule ID: SV-86825r4_rule

STIG ID: RHEL-07-030890

Severity: CAT II

See Also

https://workbench.cisecurity.org/files/2688

Item Details

Category: AUDIT AND ACCOUNTABILITY

References: 800-53|AU-12, CSCv7|6.3

Plugin: Unix

Control ID: 5d6dfc6ea3ece9456c9f37b73b0d98864b6fb98eeec217b9654a6866e4439d2a