Confinement is the process of making sure that information does not leak to unauthorized users. While confinement remains a crucial problem in secure and mission-critical applications, the confinement problem is not currently very important. To build a secure server, buy a dedicated machine, turn off all network services except the one you intend to run, and let that service performs its own authorization. Implementation bugs, such as failure to check input buffer lengths. Misused authority, where a program operating with special privilege is made to use that privilege at an inappropriate time.
Hardware bugs present important difficulties that have received inadequate attention.
Implementation bugs can usually be located by suitable quality assurance procedures, rapidly isolatable, and easily fixed. Misused authority errors are extremely subtle, take a long time to locate, and sometimes require redesign of the software. A clear example of a misused authority problem is presented in The Confused Deputy . EROS has no equivalent of the UNIX superuser authority. Capabilities refer to a specific object, so there is little risk of abuse in a typically-designed domain.