topic script to check for null passwords in Operating System - Linux

script to check for null passwords

Ragni Singh — Wed, 06 Jul 2005 10:50:03 GMT

Hello, does anyone have a script to share with me thats goes and checks for null passwords.

And also check for any user that has a GID of 0 except for root.

Thanks for the time and points will be assigned.

Re: script to check for null passwords

Ivan Ferreira — Wed, 06 Jul 2005 11:31:40 GMT

Check ID=0

grep -v root /etc/passwd | awk -F ":" '$3 == 0 { print $1 }'

Re: script to check for null passwords

Ivan Ferreira — Wed, 06 Jul 2005 11:36:36 GMT

I don't have a linux to test but i beleave that a null password has no password entry in /etc/shadow, so:

cat /etc/shadow | awk -F ":" '$2 == "" { print $1 }'

This could tell y you the username with null password.

Re: script to check for null passwords

Rick Garland — Wed, 06 Jul 2005 11:37:02 GMT

A couple of quick and dirty scripts

If you use the /etc/shadow file
cat /etc/shadow | awk -F: '{print $1, $2}'

This will list the 1st field and the 2nd field of the shadow file. If the 2nd field of the LOGNAME is blank, no passwd.

Other option is to use the passwd -S 'LOGNAME' command. This will give a verbose output of the passwd status for the account.

Example;
cat /etc/passwd | awk -F: '{print $1}' | while read line
do
passwd -S $line
done

For GID=0
cat /etc/group | awk -F: '{print $1, $3}'
This will list the LOGNAME and the GID value.

There are the GUI tools available as well that will allow you to look at the settings. No scripts required.

Re: script to check for null passwords

Rick Garland — Wed, 06 Jul 2005 11:48:04 GMT

Additional note.

Those accounts with the !! characters, the account is locked. Cannot use this account to login. These accounts may be required for applications you may have and it is OK to have these accounts locked.

Personally, I like the passwd -S $LOGNAME

Re: script to check for null passwords

Ragni Singh — Wed, 06 Jul 2005 12:19:02 GMT

Thanks, points are assigned.