Password entry

Jim Webb jrw at mtune.ATT.COM
Fri Aug 25 02:59:49 AEST 1989


In article <571 at ccssrv.UUCP>, perry at ccssrv.UUCP (Perry Hutchison) writes:
 > In article <10975 at boulder.Colorado.EDU> bobk at fred.colorado.edu (Bob Kinne)
 > writes:
 > 
 > >What is the purpose of the following /etc/passwd entry?
 > >
 > >::0:0:::	(null login, password, and shell)
 > 
 > On SunOS, an entry just like this except for a leading + means that login
 > should consult the YP (formerly "yellow pages", name changed due to
 > trademark issues) for additional valid logins.  This mechanism allows a
 > local Sun network to maintain one net-wide password file instead of having
 > to try to keep N separate files (one per system) up to date.
 > 
 > I suspect that the cited entry serves a similar purpose on your variety
 > of UN*X.

This type of entry will appear (at least with SysV) if an entry in the
passwd file is corrupted (too many or too few : fields, or a blank line)
and then the passwd program is run.  When the file is being put back
together, it comes across the wierd entry and puts back the wrong thing,
what you see above.

Remove it right away!  Why?  Well, you will notice that it is user root
(0), and, you could su to it (su "") without a need for a password.  Not
all that fun (for the admin at least :-).

-- 
Jim Webb                "Out of Phase -- Get Help"               att!mtune!jrw
#include <std/disclaimer.h>                                  jrw at mtune.att.com



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