Quick Note on Set-User-Id (SUID) flag

set-user-id (suid) flag set on file

A binary owned by root with set-user-id flag set runs with root privileges, even when an ordinary user invokes it. [2] This is useful for executables (such as pppd and cdrecord) that need to access system hardware. Lacking the suid flag, these binaries could not be invoked by a non-root user.
-rwsr-xr-t 1 root 178236 Oct 2 2000 /usr/sbin/pppd

Using chmod how to set this flag?
A numeric mode is from one to four octal digits (0-7), derived by adding up the bits with values 4, 2, and 1. Omitted digits are assumed to be leading zeros, except that if the first digit is omitted, a directory's set user and group ID bits are not affected. The first digit selects the set user ID (4) and set group ID (2) and restricted deletion or sticky (1) attributes.
The second digit selects permissions for the user who owns the file: read (4), write (2), and execute (1);
the third selects permissions for other users in the file's group, with the same values;
Fourth for other users not in the file's group, with the same values.

examples.
chmod 4777 /sbin/ifconfig
sets the set-uid bit
chmod 2777 /sbin/ifconfig
sets the set-gid bit

Comments

Rajasthan Board 10th Results | rajedubord.nic.in | RBSE

Raj Board of Secondary Education, Rajasthan Results at rajeduboard.nic.in Board of Secondary Education, Rajasthan Ajmer declared result of secondary examination today at 4PM official site is rajedubord.nic.in check Secondary Examination- 2008 Result (To be announced on July 1st, 2008 at 4:00 PM) source http:// rajresults.nic.in / Declared result Praveshika Examination-2008 Result (Announced on June 25, 2008 at 4:00 PM) The history of the Board of Secondary Education Rajasthan (BSER) is a remarkable panorama of progressive record of the futurological vision for developing a dynamic system of various sub-systems of examinations and highlights of the academic excellence of the last four decades. The BSER took rapid strides for promotion and development of Secondary Education in Rajasthan, spread over 3,42,239 sq. km. and in more than 6000 schools located in 32 districts involving 8.5 lakhs students for Secondary and Senior Secondary Examination in the year 2000. At present the Board is ...

ahsec results 2008 | www.ahsec.nic.in

The official website of assam higher secondary education council Results of Assam is down seems they are uploading results , direct link to check ahsec results 2008 is http://resultsassam.nic.in/index.asp You can find results of AHSEC at the link above. current page The Website www.ahsec.nic.in Designed Developed & Hosted by NIC, Assam State Centre, Guwahati is down for result uploading. keep checking this page, I will update as soon as news comes. All the best to AHSEC - assam higher secondary education council students. Direct links http://assam.nic.in/ www.ahsec.nic.in http://resultsassam.nic.in/

Encyclopedia of Life - by the World's Leading Scientists

An epic effort to promote biodiversity and document all 1.8 million named species on the planet. When completed, http://www.eol.org will serve as a global biodiversity tool, providing scientists, policymakers, students, and citizens information they need to discover and protect the planet and encourage learning and conservation. The Encyclopedia of Life is a collaborative scientific effort led by the Field Museum of Natural History, Harvard University, Marine Biological Laboratory, Missouri Botanical Garden, Smithsonian Institution, and Biodiversity Heritage Library, a consortium including the core institutions and also the American Museum of Natural History (New York), Natural History Museum (London), New York Botanical Garden, and Royal Botanic Gardens (Kew). clipped from www.eol.org clipped from www.eol.org "Imagine an electronic page for each species of organism on Earth, available everywhere by single access on command." - Edward O. Wilson The Encyclopedia of Life (E...

My Tech notes

Search This Blog