EP11-00-002800 - The audit information produced by the EDB Postgres Advanced Server must be protected from unauthorized deletion.
If audit data were to become compromised, then competent forensic analysis and discovery of the true source of potentially malicious system activity is impossible to achieve. To ensure the veracity of audit data, the information system and/or the application must protect audit information from unauthorized deletion. This requirement can be achieved through multiple methods which will depend upon system architecture and design. Some commonly employed methods include: ensuring log files enjoy the proper file system permissions utilizing file system protections; restricting access; and backing up log data to ensure log data is retained. Applications providing a user interface to audit data will leverage user permissions and roles identifying the user accessing the data and the corresponding rights the user enjoys to make access decisions regarding the deletion of audit data. Audit information includes all information (e.g., audit records, audit settings, and audit reports) needed to successfully audit information system activity. Deletion of database audit data could mask the theft of, or the unauthorized modification of, sensitive data stored in the database.
1) Change ownership of EDB Audit directory and its contents to the database service account if they are not owned by the database service account. If the EDB Audit directory and its contents are not owned by the database service account, change ownership to the service account responsible for running the Advanced Server database service. This may be done using Windows Explorer: Browse to the directory where the EDB audit directory folder is located. Select and right-click on the folder, select 'Properties', select the 'Securities' tab, and select the 'Advanced' button. Select the 'Change' link shown next to the owner of the folder to change the folder's owner. Alternatively, the Windows TAKEOWN command or the ICACLS command (with the /SETOWNER option) may be used to change ownership of folders and files using the Windows command prompt. 2) Modify permissions on the EDB Audit directory and its contents to meet the requirement to protect against unauthorized access. This may be done using Windows Explorer: Browse to the directory where the EDB audit directory folder is located. Select and right-click on the folder, select 'Properties', and select the 'Security' tab. Modify the security permissions to: NT AUTHORITY/NetworkService (or configured database service account) (Full Control) Administrators (Read) Users (none) Alternatively, the Windows ICACLS command may be used to modify permissions on folders and files using the Windows command prompt. If other permissions have been granted to other users or groups, ensure that the system documentation is updated to note the organizationally approved permission setting and corresponding justification of the permission settings for this requirement.