🚀 go-pugleaf

War Stories From TSO Financial - The Saga Continues...
Chapter 2 - Sunday, March 15, 1987

Being in a banking environment with over 500 users spread between 17 
buildings up and down the east coast, the use electronic mail becomes the 
major issue in communications. The solution when you have VMS is to use VMS 
MAIL and the days of telephone tag are but a lingering memory. 

The other MAJOR problem being in the banking environment is one of security 
and attempting to satisfy the auditors, both internal and external. In our 
attempts to place controls on what users can do, each has a login menu that 
presents them with access to what they need. The problem is the third party 
and in-house systems that were written with little or no thought about the 
restricted use of privileges. The idea of, 'give me SETPRV and I'll take 
what I need' is the prevalent theme. 

I can live with, to a limited degree, this attitude if the user can never 
get to the DCL prompt. Alas this is (was) my beef with the VMS MAIL program, 
and its providing the SPAWN command. 

Last week I reached by limit with people getting to DCL through MAIL and 
traveling around the system with excessive privileges. The net result was time 
spent with the fiche and patching the MAIL image so as to disable the SPAWN 
command. Note that this only removes the SPAWN command from MAIL, and as far 
as I have been able to tell, does not impact other aspects of MAIL 
operation. I have included the patches to the MAIL images for versions 
4.2 to 4.5 of VMS. Note that the patches are different between version 
4.2,4.3 and 4.4,4.5. You have to select the patches that you need based on 
the version of VMS you are running. I suggest that you COPY the current 
image of MAIL to a file named MAIL.EXE_V4X, where X represents the current 
version you are running. PREVIOUS to performing any updates to VMS, this 
MAIL.EXE_V4X file needs to be copied to the highest version of MAIL.EXE so that 
VMSINSTAL will work correctly. I have been using the patched images for some 
time now and everything, except SPAWN, works as before including SEND/EDIT.
It should also be noted that the MAIL$EDIT logical name should be define to be 
one of the following selections. 
	$define mail$edit "CALLABLE_TPU"
	$define mail$edit "CALLABLE_EDT"
The use of the logical name in referencing a command file does not work at the 
moment, according to an article in DSIN, for all cases.

The patches for VMS 4.2 and 4.3 of the MAIL image are as follows.

$PATCH/NOJOURNAL SYS$SYSTEM:MAIL.EXE
DEFINE BASE = 08BD7		!BASE ADDRESS TO PATCH INTO
REPLACE/INSTRUCTION BASE	!NOW WE PUT JUMP OVER SPAWN
"MOVAB L^00001471,R9"		!ORIGINAL INSTRUCTION AFTER REGISTER MASK
EXIT
"BRW 08CE4"			!BRANCH TO NORMAL RETURN
EXIT
UPDATE				!CREATE A NEW IMAGE WITH CHANGES
EXIT				!EXIT FROM PATCH UTILITY


The patches for VMS 4.4 and 4.5 of the MAIL image are as follows.

$PATCH/NOJOURNAL SYS$SYSTEM:MAIL.EXE
DEFINE BASE = 0ACA8		!BASE ADDRESS TO PATCH INTO
REPLACE/INSTRUCTION BASE	!NOW WE PUT JUMP OVER SPAWN
"SUBL2 #18,SP"			!ORIGINAL INSTRUCTION AFTER REGISTER MASK
EXIT
"BRW 0ADDD"			!BRANCH TO NORMAL RETURN
EXIT
UPDATE				!CREATE A NEW IMAGE WITH CHANGES
EXIT				!EXIT FROM PATCH UTILITY

I hope that these patches help anyone that is having problems with MAIL and 
inquisitive people with time on their hands.

Paul D. Clayton - Systems Manager
TSO Financial - Horsham, Pa. USA
Address - CLAYTON%XRT@CIS.UPENN.EDU