||Home||Switchboard||Unix Administration||Red Hat||TCP/IP Networks||Neoliberalism||Toxic Managers|
|(slightly skeptical) Educational society promoting "Back to basics" movement against IT overcomplexity and bastardization of classic Unix|
|News||Access Control||Recommended Links||Rainbow Books||Root Account||The /etc/passwd File||Root Security|
|ACL||Solaris ACLs||Linux ACL||Solaris RBAC||Sudo||PAM||UID policy|
|Group administration||Wheel Group||Authentication||Unix permissions model||History||Humor||Etc|
The /etc/passwd file can be thought of as a simple flat database that lists all of the users on the system. It is possible to configure a Unix system to use other directory services, such as NIS, LDAP, and/or Kerberos. When these systems are used, the Unix operating system is often modified so that the system programs and applications are can still think that all of the account information still reside in a /etc/passwd file. In a way they create virtual /etc/passwd file. If LDAP became unavailable the authentication goes back to passwd authentication.
On most Unix systems the passwords for these accounts are kept in a file named /etc/shadow, or /etc/security/passwd. T
newkey -u usernameOr, you can create an entry in the database for the nobody user account, and then any user can run the chkey program to create their own entries in the database without logging in as root.
Each flavor of Unix provides a default set of system special user accounts that prevents the root and system accounts from owning all operating system files and file systems.
Attention: Use caution when removing a system special user account. You can disable a specific account by inserting an asterisk (*) at the beginning of its corresponding line of the /etc/shadow file. However, be careful not to disable the root user account. If you remove system special user accounts or disable the root account, the operating system will not function.
During installation of the operating system, a number of default user and group IDs are created. Depending on the applications you are running on your system and where your system is located in the network, some of these user and group IDs can become security weaknesses, vulnerable to exploitation. If these users and group IDs are not needed, you can remove them to minimize security risks associated with them.
The following table lists the most common default user IDs that you might be able to remove:
|uucp, nuucp||Owner of hidden files used by uucp protocol. The uucp user account is used for the UNIX-to-UNIX Copy Program, which is a group of commands, programs, and files, present on most AIX systems, that allows the user to communicate with another AIX system over a dedicated line or a telephone line.|
|lpd||Owner of files used by printing subsystem|
|guest||Allows access to users who do not have access to accounts|
The following table lists common groups that might not be needed:
|uucp||Group to which uucp and nuucp users belong|
|printq||Group to which lpd user belongs|
Analyze your system to determine which IDs are indeed not needed. There might also be additional user and group IDs that you might not need. Before your system goes into production, perform a thorough evaluation of available IDs.
|User Name||User ID||Description|
|daemon||1||Umbrella system daemon associated with routine system tasks.|
|bin||2||Administrative daemon associated with running system binaries to perform some routine system task.|
|sys||3||Administrative daemon associated with system logging or updating files in temporary directories.|
|adm||4||Administrative daemon associated with system logging.|
|lp||71||Line printer daemon.|
|uucp||5||Daemon associated with uucp functions.|
|nuucp||6||Daemon associated with uucp functions.|
|smmsp||25||Sendmail message submission program daemon.|
|listen||37||Network listener daemon.|
|nobody||60001||Assigned to users or software processes that do not need nor should have any special permissions.|
|noaccess||60002||Assigned to a user or a process that needs access to a system through some application but without actually logging in.|
|nobody4||65534||SunOS 4.0 or 4.1 version of the nobody user account.|
In Table 2-1, you'll find the standard users set up by the installation process (this is essentially the /etc/passwd file). The Group ID (GID) in this table is the primary group for the user. See the section called User Private Groups for details on how groups are used.
Table 2-1. Standard Users
User UID GID Home Directory Shell root 0 0 /root /bin/bash bin 1 1 /bin daemon 2 2 /sbin adm 3 4 /var/adm lp 4 7 /var/spool/lpd sync 5 0 /sbin /bin/sync shutdown 6 0 /sbin /sbin/shutdown halt 7 0 /sbin /sbin/halt 8 12 /var/spool/mail news 9 13 /var/spool/news uucp 10 14 /var/spool/uucp operator 11 0 /root games 12 100 /usr/games gopher 13 30 /usr/lib/gopher-data ftp 14 50 /home/ftp nobody 99 99 /
This is not strictly openldap, but it should be a common problem. I am
suprised nobody ran into this earlier.
Here is an interesting inter-nonoperability issue. So I used the migrate scripts from PADL to dump NIS+ user and group maps into an LDAP directory.
Well and good. However, Solaris stores the primary group membership information in the gid field in the passwd map. As Unix usually does. :)
Enter auth_ldap, authentication module for Apache. When I use the "require valid group" directive, the code searches the group entry for the "member"
attribute with the value of the current user. The trouble is, there usually are none, because the group map on NIS+ did not define it, except in the
case of secondary groups.
Not that it's very diffucult to manually hack this, but there has got to be an official solution!
Thanks in advance,
Simon (Vsevolod ILyushchenko) firstname.lastname@example.org
Google matched content
Security Guide - Security Guide Aix52 security guide
Security Guide - System Special User Accounts
Groupthink : Two Party System as Polyarchy : Corruption of Regulators : Bureaucracies : Understanding Micromanagers and Control Freaks : Toxic Managers : Harvard Mafia : Diplomatic Communication : Surviving a Bad Performance Review : Insufficient Retirement Funds as Immanent Problem of Neoliberal Regime : PseudoScience : Who Rules America : Neoliberalism : The Iron Law of Oligarchy : Libertarian Philosophy
War and Peace : Skeptical Finance : John Kenneth Galbraith :Talleyrand : Oscar Wilde : Otto Von Bismarck : Keynes : George Carlin : Skeptics : Propaganda : SE quotes : Language Design and Programming Quotes : Random IT-related quotes : Somerset Maugham : Marcus Aurelius : Kurt Vonnegut : Eric Hoffer : Winston Churchill : Napoleon Bonaparte : Ambrose Bierce : Bernard Shaw : Mark Twain Quotes
Vol 25, No.12 (December, 2013) Rational Fools vs. Efficient Crooks The efficient markets hypothesis : Political Skeptic Bulletin, 2013 : Unemployment Bulletin, 2010 : Vol 23, No.10 (October, 2011) An observation about corporate security departments : Slightly Skeptical Euromaydan Chronicles, June 2014 : Greenspan legacy bulletin, 2008 : Vol 25, No.10 (October, 2013) Cryptolocker Trojan (Win32/Crilock.A) : Vol 25, No.08 (August, 2013) Cloud providers as intelligence collection hubs : Financial Humor Bulletin, 2010 : Inequality Bulletin, 2009 : Financial Humor Bulletin, 2008 : Copyleft Problems Bulletin, 2004 : Financial Humor Bulletin, 2011 : Energy Bulletin, 2010 : Malware Protection Bulletin, 2010 : Vol 26, No.1 (January, 2013) Object-Oriented Cult : Political Skeptic Bulletin, 2011 : Vol 23, No.11 (November, 2011) Softpanorama classification of sysadmin horror stories : Vol 25, No.05 (May, 2013) Corporate bullshit as a communication method : Vol 25, No.06 (June, 2013) A Note on the Relationship of Brooks Law and Conway Law
Fifty glorious years (1950-2000): the triumph of the US computer engineering : Donald Knuth : TAoCP and its Influence of Computer Science : Richard Stallman : Linus Torvalds : Larry Wall : John K. Ousterhout : CTSS : Multix OS Unix History : Unix shell history : VI editor : History of pipes concept : Solaris : MS DOS : Programming Languages History : PL/1 : Simula 67 : C : History of GCC development : Scripting Languages : Perl history : OS History : Mail : DNS : SSH : CPU Instruction Sets : SPARC systems 1987-2006 : Norton Commander : Norton Utilities : Norton Ghost : Frontpage history : Malware Defense History : GNU Screen : OSS early history
The Peter Principle : Parkinson Law : 1984 : The Mythical Man-Month : How to Solve It by George Polya : The Art of Computer Programming : The Elements of Programming Style : The Unix Haterís Handbook : The Jargon file : The True Believer : Programming Pearls : The Good Soldier Svejk : The Power Elite
Most popular humor pages:
Manifest of the Softpanorama IT Slacker Society : Ten Commandments of the IT Slackers Society : Computer Humor Collection : BSD Logo Story : The Cuckoo's Egg : IT Slang : C++ Humor : ARE YOU A BBS ADDICT? : The Perl Purity Test : Object oriented programmers of all nations : Financial Humor : Financial Humor Bulletin, 2008 : Financial Humor Bulletin, 2010 : The Most Comprehensive Collection of Editor-related Humor : Programming Language Humor : Goldman Sachs related humor : Greenspan humor : C Humor : Scripting Humor : Real Programmers Humor : Web Humor : GPL-related Humor : OFM Humor : Politically Incorrect Humor : IDS Humor : "Linux Sucks" Humor : Russian Musical Humor : Best Russian Programmer Humor : Microsoft plans to buy Catholic Church : Richard Stallman Related Humor : Admin Humor : Perl-related Humor : Linus Torvalds Related humor : PseudoScience Related Humor : Networking Humor : Shell Humor : Financial Humor Bulletin, 2011 : Financial Humor Bulletin, 2012 : Financial Humor Bulletin, 2013 : Java Humor : Software Engineering Humor : Sun Solaris Related Humor : Education Humor : IBM Humor : Assembler-related Humor : VIM Humor : Computer Viruses Humor : Bright tomorrow is rescheduled to a day after tomorrow : Classic Computer Humor
The Last but not Least Technology is dominated by two types of people: those who understand what they do not manage and those who manage what they do not understand ~Archibald Putt. Ph.D
Copyright © 1996-2021 by Softpanorama Society. www.softpanorama.org was initially created as a service to the (now defunct) UN Sustainable Development Networking Programme (SDNP) without any remuneration. This document is an industrial compilation designed and created exclusively for educational use and is distributed under the Softpanorama Content License. Original materials copyright belong to respective owners. Quotes are made for educational purposes only in compliance with the fair use doctrine.
FAIR USE NOTICE This site contains copyrighted material the use of which has not always been specifically authorized by the copyright owner. We are making such material available to advance understanding of computer science, IT technology, economic, scientific, and social issues. We believe this constitutes a 'fair use' of any such copyrighted material as provided by section 107 of the US Copyright Law according to which such material can be distributed without profit exclusively for research and educational purposes.
This is a Spartan WHYFF (We Help You For Free) site written by people for whom English is not a native language. Grammar and spelling errors should be expected. The site contain some broken links as it develops like a living tree...
|You can use PayPal to to buy a cup of coffee for authors of this site|
Last modified: March 12, 2019