su to user without knowing the password

[Petr Simik]

Can some ordinarry user SU to another user without knowing the password? (as root)
Can I setup (configure) some trustings?

[Pete Randall]

AFAIK, only root is able to su to another user without providing the password - and I sincerely hope that no one proves me wrong.

Pete

[steven Burgess_2]

Hi

I think your pretty safe with that reply Pete

Regs

Steve

[Darren Prior]

The man page for su(1) backs you up Pete :)

"To use su, the appropriate password must be supplied unless the current user is superuser."

regards,

Darren.

[Chris Wilshaw · Accepted solution]

You should be able to do this using sudo

Download it from

http://hpux.cs.utah.edu/hppd/hpux/Sysadmin/sudo-1.6.2b1/

[Keith Clark]

This may work depending upon your requirements and a couple of dependancies. You can do it on the same machine or between machines. For this example I will use the same machine, called mymach and two users: user1 and user2 (how original!)

As user2, cd to your home directory and 'echo "mymach user1" >> .rhosts'

As long as remsh service is enabled and you can resolve mymach, you now should be able to execute as user1 'remsh mymach -l user2 '

It's not pretty, but it works.

Keith

[Brian Kinney]

su itself is quite secure. However, there are other tools which allow users to utilize other people's accounts.

.rhosts files are easy ways to bypass the passwd - if rsh,rlogin are on, you can act as another user as long as your ID is listed in the .rhosts file.

This is usually a security issue for a number of reasons:

1) poor syntax in the .rhosts file can lead to a server compromise. If Bob has a .rhosts file which says:

ralph bigserver
dave

Then ANY system which can answer as "bigserver" with a userid of "ralph" on it can gain access without a passwd. The "dave" entry is worse, as it doesn't care which server has a userid of "dave" it will have access.

This is how I accessed a server which lost the root passwd - through .rhost files. We saw the .rhosts file was readable for root, and saw a non-root user who was in the list. We logged into another UNIX host, su'd to that user, then used rlogin as root to access the locked out host, all without knowing the root passwd.

2) Daisychaining across hosts - Since many people use NFS to deliver /home/ , it will unwittingly give others inbound access to servers which the "account owner" never intended. For instance, Bob and Dave allow .rhosts between each other. Ralph convinces Bob that they should also share .rhosts. Bob has just given Ralph access to Dave's accounts.

[Sean OB_1]

Via regular su only superuser can switch to another user without the password.

If you use "sudo" then you can set it up to allow a particular user to su to another user, and they won't need the password.

sudo lets them run the su command as root.

http://www.courtesan.com for sudo.