From Bugzilla Helper:
User-Agent: Mozilla/4.78 [en] (X11; U; Linux 2.4.9-31 i686)

Description of problem:
newgrp will not allow unpriveleged users to change to a passworded group of
which they are not a member, even if they authenticate with the proper group
password.

Version-Release number of selected component (if applicable):
newgrp from: util-linux-2.11f-17
shadow from: shadow-utils-20000902-4

How reproducible:
Always

Steps to Reproduce:
As root:
   1. groupadd test
   2. gpasswd test  # Password: testing

As user:
   1. newgrp test   # Password: testing

Actual Results:  newgrp: Permission denied

Expected Results:  GID should have been changed to "test" and other groups
should have become secondaries.

Additional info:

newgrp from: util-linux-2.11f-17
shadow from: shadow-utils-20000902-4