Title

Successful/unsuccessful uses of the creat system call in TOSS must generate an audit record. (Cat II impact)

Discussion

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 "creat" system call is used to open and possibly create a file or device. 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. Satisfies: SRG-OS-000064-GPOS-00033, SRG-OS-000474-GPOS-00219

Check Content

Verify TOSS generates an audit record when successful/unsuccessful attempts to use the "creat" system call by performing the following command to check the file system rules in "/etc/audit/audit.rules": $ sudo grep -iw creat /etc/audit/audit.rules -a always,exit -F arch=b32 -S creat -F exit=-EPERM -F auid>=1000 -F auid!=unset -k perm_access -a always,exit -F arch=b64 -S creat -F exit=-EPERM -F auid>=1000 -F auid!=unset -k perm_access -a always,exit -F arch=b32 -S creat -F exit=-EACCES -F auid>=1000 -F auid!=unset -k perm_access -a always,exit -F arch=b64 -S creat -F exit=-EACCES -F auid>=1000 -F auid!=unset -k perm_access If the command does not return all lines, or the lines are commented out, this is a finding.

Fix Text

Configure the audit system to generate an audit event for any successful/unsuccessful use of the "creat" system call by adding or updating the following rules in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F arch=b32 -S creat -F exit=-EPERM -F auid>=1000 -F auid!=unset -k perm_access -a always,exit -F arch=b64 -S creat -F exit=-EPERM -F auid>=1000 -F auid!=unset -k perm_access -a always,exit -F arch=b32 -S creat -F exit=-EACCES -F auid>=1000 -F auid!=unset -k perm_access -a always,exit -F arch=b64 -S creat -F exit=-EACCES -F auid>=1000 -F auid!=unset -k perm_access The audit daemon must be restarted for the changes to take effect.

Additional Identifiers

Rule ID: SV-253011r958446_rule

Vulnerability ID: V-253011

Group Title: SRG-OS-000064-GPOS-00033

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.