Original sentence: In some cases, the root account is disabled by default, and must be specifically enabled.Many operating systems, such as Mac OS X and some Linux distributions, allow administrator accounts which provide greater access while shielding the user from most of the pitfalls of full root access.One common way of gaining root is to cause a buffer overflow in a program already running with superuser privileges.Software defects which allow a user to "gain root" (to execute with superuser privileges code supplied by that user) are a major computer security issue, and the fixing of such software is a major part of maintaining a secure system
Edited sentence: Many operating systems, such as Mac OS X asome cases, the root account is disabled by default, and must be specifically enabled.Software defects which allow a user to "gain root" (to execute with superuser privileges code supplied by that user) are a major computer security issue, and the fixing of such software is a major part of maintainiprivileges