OL08-00-030420 - OL 8 must generate audit records for any use of the 'truncate', 'ftruncate', 'creat', 'open', 'openat', and 'open_by_handle_at' system calls.

Information

Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one.

Audit records can be generated from various components within the information system (e.g., module or policy filter). The 'truncate' and 'ftruncate' functions are used to truncate a file to a specified length.
The 'creat' system call is used to open and possibly create a file or device.
The 'open' system call opens a file specified by a pathname. If the specified file does not exist, it may optionally be created by 'open'.
The 'openat' system call opens a file specified by a relative pathname.
The 'name_to_handle_at' and 'open_by_handle_at' system calls split the functionality of openat into two parts: 'name_to_handle_at' returns an opaque handle that corresponds to a specified file; 'open_by_handle_at' opens the file corresponding to a handle returned by a previous call to 'name_to_handle_at' and returns an open file descriptor.

When a user logs on, the AUID is set to the UID of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to '-1'. The AUID representation is an unsigned 32-bit integer, which equals '4294967295'. The audit system interprets '-1', '4294967295', and 'unset' in the same way.

The system call rules are loaded into a matching engine that intercepts each syscall that all programs on the system makes. Therefore, it is very important to only use syscall rules when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. Performance can be helped, though, by combining syscalls into one rule whenever possible.

Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000064-GPOS-00033, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215

Solution

Configure the audit system to generate an audit event for any use of the 'truncate', 'ftruncate', 'creat', 'open', 'openat', and 'open_by_handle_at' system calls by adding or updating the following rules in the '/etc/audit/rules.d/audit.rules' file:

-a always,exit -F arch=b32 -S truncate,ftruncate,creat,open,openat,open_by_handle_at -F exit=-EPERM -F auid>=1000 -F auid!=unset -k perm_access
-a always,exit -F arch=b64 -S truncate,ftruncate,creat,open,openat,open_by_handle_at -F exit=-EPERM -F auid>=1000 -F auid!=unset -k perm_access

-a always,exit -F arch=b32 -S truncate,ftruncate,creat,open,openat,open_by_handle_at -F exit=-EACCES -F auid>=1000 -F auid!=unset -k perm_access
-a always,exit -F arch=b64 -S truncate,ftruncate,creat,open,openat,open_by_handle_at -F exit=-EACCES -F auid>=1000 -F auid!=unset -k perm_access

The audit daemon must be restarted for the changes to take effect. To restart the audit daemon, run the following command:

$ sudo service auditd restart

Item Details

Audit Name: DISA Oracle Linux 8 STIG v2r1

Category: AUDIT AND ACCOUNTABILITY, MAINTENANCE

Plugin: Unix

Control ID: 2b761004f58f0af909c95005c0e34fbe483072e5a5be63e4d0a2f852c91d6d38

Detections

Analytics

OL08-00-030420 - OL 8 must generate audit records for any use of the 'truncate', 'ftruncate', 'creat', 'open', 'openat', and 'open_by_handle_at' system calls.

Information

Solution

See Also

Item Details