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Re: User management

 
Pluto_2
Occasional Advisor

User management

Hi Experts,

Could you let me know, is it possible to assign same uid to different users?

Thanks and Regards,

Rahul Kumar
7 REPLIES 7
Oviwan
Honored Contributor

Re: User management

no. if you want to do it for folder permission you can do it with the gid.

hth
Pluto_2
Occasional Advisor

Re: User management

Hi Experts,

But I am seeing so many users on my one server that are having same user Id.

====================================

ew3284:x:60001:29000:Evelyn Walters:/home/sadm/ew3284:/usr/bin/ksh
ww3584:x:60001:29000:William Wilson:/home/sadm/ww3584:/usr/bin/ksh
rd2197:x:60001:29000:Ronald Dunn:/home/sadm/rd2197:/usr/bin/ksh
pd2184:x:60001:29000:Phillip Dinkins:/home/sadm/pd2184:/usr/bin/ksh
ws2851:x:60001:29000:William Shelton:/home/sadm/ws2851:/usr/bin/ksh
rs7161:x:60001:29000:Robert Surber:/home/sadm/rs7161:/usr/bin/ksh
sb878q:x:60001:1229:Sudip Basnet:/home/acsisupt/sb878q:/usr/bin/ksh
qw321v:x:60001:187:Quincy Washington:/home/nbu/qw321v:/usr/bin/ksh
nv8510:x:60001:350:Neeraj Vashisht:/home/oper/nv8510:/usr/bin/ksh
ms945x:x:60001:350:Mehul Sharma:/home/oper/ms945x:/usr/bin/ksh
rr221v:x:60001:350:Rajesh Rajput:/home/oper/rr221v:/usr/bin/ksh
aa686w:x:60001:350:Ankit Aggarwal:/home/oper/aa686w:/usr/bin/ksh
pk161j:x:60001:350:Panda Kaustav:/home/oper/pk161j:/usr/bin/ksh
pg8524:x:8524:48597:Peter Gun :/home/sdbuild/pg8524:/usr/bin/ksh
sa099k:x:3915157:1229:Sukumar Arumugam:/home/acsisupt/sa099k:/usr/bin/ksh


Please suggets on this. Is it possible?
Kapil Jha
Honored Contributor

Re: User management

If two users are assigned the same UID , UNIX views them as the same user, even if they have different usernames and passwords. Two users with the same UID can freely read and delete each other's files and can kill each other's programs. Giving two users the same UID is almost always a bad idea;

BR,
Kapil+
I am in this small bowl, I wane see the real world......
Kapil Jha
Honored Contributor

Re: User management

Refer this link.

http://docstore.mik.ua/orelly/networking/puis/ch04_01.htm


BR,
Kapil+
I am in this small bowl, I wane see the real world......
Kapil Jha
Honored Contributor

Re: User management

Pluto,

You are in deep trouble my firend, you need to change the user-id,
your system is really messed up :)

clear the mess, and make user id unique for every user.

BR,
Kapil+
I am in this small bowl, I wane see the real world......
Bill Hassell
Honored Contributor

Re: User management

> is it possible to assign same uid to different users?

Yes, and you are seeing that already. Use the command:

logins -d

And you'll see the problem. A user name is nothing more than a symbolic name, similar to a hostname. The UID is the real ID, while the username is just an alias to the UID number.

Additionally, hackers will often hijack a username and change the UID to 0, thus ctreating a duplicate root user (a big security problem).


Bill Hassell, sysadmin
Viktor Balogh
Honored Contributor

Re: User management

Hi,

This is a bad config, I have encountered it already at one of our customers. The thing is that they interpreted the unix rights wrong. For this they should have used the GID. For easily changing the UID, use my performance-optimized script:

http://viktorbalogh.net/blog/languages_scripting/advanced-scripting-changing-the-uid-of-a-user

It starts parallel (find├в ┬ж.chown) processes to get the job done as fast as it can be.

Regards,
Viktor
****
Unix operates with beer.