Editing Setuid (section)

{{short description|Unix access rights flag}}
{{Lowercase title}}
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The [[Unix]] and [[Linux]] access rights flags '''setuid''' and '''setgid''' (short for ''set user identity'' and ''set group identity'')<ref>{{cite book|first=William |last=von Hagen |title=Ubuntu Linux Bible|url=https://books.google.com/books?id=rsSlrQLB8-gC&q=set%20user%20ID%20upon%20execution&pg=SA3-PA59 |pages=3–59|isbn=9780470881804|date=2010-05-13|publisher=John Wiley & Sons }}</ref> allow users to run an [[executable]] with the [[file system permissions]] of the executable's owner or group respectively and to change behaviour in directories. They are often used to allow users on a computer system to run programs with temporarily elevated privileges to perform a specific task.  While the assumed user id or group id privileges provided are not always elevated, at a minimum they are specific.

The flags <code>setuid</code> and <code>setgid</code> are needed for tasks that require different privileges than what the user is normally granted, such as the ability to alter system files or databases to change their login password.<ref name="oreilly">{{cite book|first=Æleen |last=Frisch |title=Essential system administration| url=https://books.google.com/books?id=uRW8V9QOL7YC&q=setuid&pg=PT375 |page=351|publisher= O'Reilly|isbn=9780596550493|date=2009-02-09}}</ref> Some of the tasks that require additional privileges may not immediately be obvious, though, such as the <code>[[ping (networking utility)|ping]]</code> command, which must send and listen for [[Internet Control Message Protocol|control packet]]s on a network interface.