Securing pgm folder on IFS

Our company recently underwent penetration testing from an outside vendor.  Auditors are on the prowl.

The penetration tester (former hacker) was able to map a drive as anonymous and modify one of our .sh scripts (BAD).

We removed GUEST in Netserver to resolve that issue.

However mgmt wants to further lock down of our program folder on the IFS (primarily .py, .sh, .json).

We implemented the following:

We created two group profiles:  TESTDEV and TESTAPPS
We created two user profiles:  TESTPGMR and TESTUSER

TESTPGMR is a class *QPGMR, no special authorities, and has supplemental group TESTDEV.
TESTUSER is class *QPGMR, no special authorities, and has supplemental group TESTAPPS.


Programs are in /testapps/TESTPGP.

We ran the following changes:

chown -R testdev /testapps/TESTPGP.
chgrp -R testapps /testapps/TESTPGP.
chmod -R 750 /testapps/TESTPGP.

This allows for the pgmr to develop code; users to run code; and public is locked out.

This folder looks like this now:

ls -al /testapps/TESTPGP
total 200
drwxr-s---    3 testdev  testapps       8192 Oct 12 16:21 .
drwx--Srwx   10 testown  0             28672 Jun 28 14:48 ..
-rwxr-x---    1 testdev  testapps       6270 Dec 14 2022 TESTPGP2.py
-rwxr-x---    1 testdev  testapps        190 Jul 23 20:26 TESTPGP2.sh

We tested:

1.  Ability of anonymous user on a mapped drive changing anything in  /testapps/TESTPGP -- FAIL
2.  Ability of TESTPGMR to change/creaste pgms in /testapps/TESTPGP -- PASS
3.  Ability of TESTUSER to run pgms in /testapps/TESTPGP -- PASS

After further testing somehow the group in /testapps/TESTPGP was changed to 121.

Now we can't run chgrp on the *IX side and get this message:

0481-002 chgrp: testapps is not a recognized group.  Check the /etc/group file for all known groups.

There is NO file /etc/group.

We see there is a db2 cmd Change Primary Group (CHGPGP).

Changing the group on the db2 does not change the group in ls -al /testapps/TESTPGP.

What is the relationship between chgrp and CHGPGP?

Seems like since all of our code runs on the *IX side of the IBM I we need chgrp.

Stuck here.

Thanks,

Jerry