II.C.15(a)     Operating System Access

Access to the operating system and system utilities provide users with the authority to make fundamental changes to the system. System utilities are programs that perform repetitive functions, such as creating, deleting, changing, or copying files. System utilities also could include numerous types of system management software that can supplement operating system functionality by supporting common system tasks, such as security, system monitoring, or transaction processing.

Unauthorized access to the operating system and system utilities could result in significant financial and operational losses. System and security administrators should restrict and monitor privileged access to operating systems and system utilities. Many operating systems have integrated or third-party access control software, which is often essential to effective access control and can be used to integrate the security management of the operating system and applications. To prevent unauthorized access to or inappropriate activity on the operating system and system utilities, management should do the following:

  • Implement effective user access to appropriately restrict system access for both users and applications and, depending on the sensitivity, extend protection at the program, file, record, or field level.
  • Limit the number of employees with access to operating systems and grant only the minimum level of access required to perform job responsibilities.
  • Restrict and log access to and activity on operating system parameters, system utilities (especially those with data-altering capabilities), and sensitive system resources (including files, programs, and processes), and supplement with additional security software, as necessary.
  • Restrict operating system access to specific terminals in physically secure and monitored locations.
  • Secure or remove external drives and portable media from system consoles, terminals, or personal computers (PC) running terminal emulations, residing outside of physically secure locations.
  • Prohibit remote access to operating system and system utilities, where feasible, and, at a minimum, require strong authentication and encrypted sessions before allowing such remote access.
  • Filter and review logs for potential security events and provide adequate reports and alerts.
  • Independently monitor operating system access by user, terminal, date, and time of access.


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II.C.15 Logical Security
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II.C.15(b) Application Access