Share your story
The central voice for Linux and Open Source security news
Home News Topics Advisories HOWTOs Features Newsletters About Register

Sign up!
EnGarde Community
What is the most important Linux security technology?
Linux Events
Linux User Groups
Link to Us
Security Center
Book Reviews
Security Dictionary
Security Tips
White Papers
Featured Blogs
All About Linux
DanWalsh LiveJournal
Latest Newsletters
Linux Security Week: March 30th, 2015
Linux Advisory Watch: March 27th, 2015
LinuxSecurity Newsletters
Choose Lists:
About our Newsletters
RSS Feeds
Get the LinuxSecurity news you want faster with RSS
Powered By

Using sudo Print E-mail
User Rating:      How can I rate this item?
Source: Dave Wreski - Posted by Dave Wreski   
Learn tips and tricks sudo is a mechanism of providing root prileges to an ordinary user

If you absolutely positively need to allow someone (hopefully very trusted) to have superuser access to your machine, there are a few tools that can help. sudo allows users to use their password to access a limited set of commands as root. sudo keeps a log of all successful and unsuccessful sudo attempts, allowing you to track down who used what command to do what. For this reason sudo works well even in places where a number of people have root access, but use sudo so you can keep track of changes made.

Although sudo can be used to give specific users specific privileges for specific tasks, it does have several shortcomings. It should be used only for a limited set of tasks, like restarting a server, or adding new users. Any program that offers a shell escape will give the user root access. This includes most editors, for example. Also, a program as innocuous as /bin/cat can be used to overwrite files, which could allow root to be exploited. Consider sudo as a means for accountability, and don't expect it to replace the root user, yet be secure.

To do almost any administrative function in Linux one requires root (privileged) access. Unfortunately the built in mechanisms that can be used to grant this type of access are relatively weak. The primary tool is "su" which lets you run a shell as another user, unfortunately you need the other user's password, so everyone you want to grant root access will have the password and unrestricted access. A slightly more fine grained tool is the setuid or setgid bit, if this is set on a file, then the file runs as the user or group that owns it (typically root). Managing file permissions, and ensuring there are no bugs in the program that can be used to gain full root access is difficult at best.

More information:

There are several tools that let you tightly control root access to various programs, they all act as intermediaries, checking who has called them, possibly asking for a password, and applying other criteria before executing the program in quesiton as root.

Sudo gives a user setuid access to a program, and you can specify which hosts they are allowed to login from (or not) and have sudo access. You can specify what user a command will run as, giving you a relatively fine degree of control. Sudo now ships with some Linux distributions, and binary packages / source are widely available.

Super can be used to give certain users (and groups) varied levels of access to system administration. In addition to this you can specify times and allow access to scripts. Debian ships with super, and there are binary packages and source widely available.

runas let's you define a configuration file listing the command, who it runs as, and which users/groups/etc. are allowed to run it.. In addition to this you can restrict the use of options (arguments), and you can prompt the user for a reason (which is logged to syslog).

Downloads: - sudo

sudo userWritten by Jorge Delacruz on 2007-11-27 12:10:24
Is there a way to use sudo to limit the number of people accessing root, or to block shell escapes? These questions should be addressed in this article.

Only registered users can write comments.
Please login or register.

Powered by AkoComment!

< Prev   Next >


Latest Features
Peter Smith Releases Linux Network Security Online
Securing a Linux Web Server
Password guessing with Medusa 2.0
Password guessing as an attack vector
Squid and Digest Authentication
Squid and Basic Authentication
Demystifying the Chinese Hacking Industry: Earning 6 Million a Night
Free Online security course (LearnSIA) - A Call for Help
What You Need to Know About Linux Rootkits
Review: A Practical Guide to Fedora and Red Hat Enterprise Linux - Fifth Edition
Yesterday's Edition
Feds Charged With Stealing Money During Silk Road Investigation
EFF questions US government's software flaw disclosure policy
Hotel Router Vulnerability A Reminder Of Untrusted WiFi Risks
Partner Sponsor

Community | HOWTOs | Blogs | Features | Book Reviews | Networking
 Security Projects |  Latest News |  Newsletters |  SELinux |  Privacy |  Home
 Hardening |   About Us |   Advertise |   Legal Notice |   RSS |   Guardian Digital
(c)Copyright 2015 Guardian Digital, Inc. All rights reserved.