Here's another funny story from my email archives of around the same time, about how Jordan Hubbard's infamous rwall almost got UC Berkeley cut off from the internet, with some more interesting details from other old net boys like Milo Medin, Marc Crispin, and Dennis G. Perry:

https://news.ycombinator.com/item?id=31822138

Speaking of YP (which I always thought sounded like a brand of moist baby poop towelettes), BSD, wildcard groups, SunRPC, and Sun's ingenuous networking and security and remote procedure call infrastructure, who remembers Jordan Hubbard's infamous rwall incident on March 31, 1987?

https://news.ycombinator.com/item?id=25156006

https://en.wikipedia.org/wiki/Jordan_Hubbard#rwall_incident

>rwall incident

>On March 31, 1987 Hubbard executed an rwall command expecting it to send a message to every machine on the network at University of California, Berkeley, where he headed the Distributed Unix Group. The command instead began broadcasting Hubbard's message to every machine on the internet and was stopped after Hubbard realised the message was being broadcast remotely after he received complaints from people at Purdue University and University of Texas. Even though the command was terminated, it resulted in Hubbard receiving 743 messages and complaints, including one from the Inspector General of ARPAnet.

I was logged in on my Sun workstation "tumtum" when it happened, so I received his rwall too, and immediately sent him a humorous email with the subject of "flame flame flame" which I've lost in the intervening 35 years, but I still have a copy of his quick reply:

From: Jordan K. Hubbard <jkh%violet.Berkeley.EDU@berkeley.edu>
Date: Tue, Mar 31, 1987, 11:02 PM
To: Don Hopkins <don@tumtum.cs.umd.edu>
Subject: re: flame flame flame

Thanks, you were nicer than most.. Here's the stock letter I've been
sending back to people:

Thank you, thank you..

Now if I can only figure out why a lowly machine in a basement somewhere
can send broadcast messages to the entire world. Doesn't seem *right*
somehow.

Yours for an annoying network.

Jordan

P.S. I was actually experimenting to see exactly now bad a crock RPC was.
I'm beginning to get an idea. I look forward to your flame.

Jordan

Here's the explanation he sent to hackers_guild, and some replies from old net boys like Milo Medin (who said the program manager of the Arpanet in the Information Science and Technology Office of DARPA Dennis G. Perry said they would kick UCB off the Arpanet if it ever happened again), Mark Crispin (who presciently proposed cash rewards for discovering and disclosing security bugs), and Dennis G. Perry himself:

From: Jordan K. Hubbard <jkh%violet.Berkeley.EDU@berkeley.edu>
Date: April 2, 1987
Subject: My Broadcast

By now, many of you have heard of (or seen) the broadcast message I sent to
the net two days ago. I have since received 743 messages and have
replied to every one (either with a form letter, or more personally
when questions were asked). The intention behind this effort was to
show that I wasn't interested in doing what I did maliciously or in
hiding out afterwards and avoiding the repercussions. One of the
people who received my message was Dennis Perry, the Inspector General
of the ARPAnet (in the Pentagon), and he wasn't exactly pleased.
(I hear his Interleaf windows got scribbled on)

So now everyone is asking: "Who is this Jordan Hubbard, and why is he on my
screen??"

I will attempt to explain.

I head a small group here at Berkeley called the "Distributed Unix Group".
What that essentially means is that I come up with Unix distribution software
for workstations on campus. Part of this job entails seeing where some of
the novice administrators we're creating will hang themselves, and hopefully
prevent them from doing so. Yesterday, I finally got around to looking
at the "broadcast" group in /etc/netgroup which was set to "(,,)". It
was obvious that this was set up for rwall to use, so I read the documentation
on "netgroup" and "rwall". A section of the netgroup man page said:

...
Any of three fields can be empty, in which case it signifies
a wild card. Thus
universal (,,)
defines a group to which everyone belongs. Field names that ...
...

Now "everyone" here is pretty ambiguous. Reading a bit further down, one
sees discussion on yellow-pages domains and might be led to believe that
"everyone" was everyone in your domain. I know that rwall uses point-to-point
RPC connections, so I didn't feel that this was what they meant, just that
it seemed to be the implication.

Reading the rwall man page turned up nothing about "broadcasts". It doesn't
even specify the communications method used. One might infer that rwall
did indeed use actual broadcast packets.

Failing to find anything that might suggest that rwall would do anything
nasty beyond the bounds of the current domain (or at least up to the IMP),
I tried it. I knew that rwall takes awhile to do its stuff, so I left
it running and went back to my office. I assumed that anyone who got my
message would let me know.. Boy, was I right about that!

After the first few mail messages arrived from Purdue and Utexas, I begin
to understand what was really going on and killed the rwall. I mean, how
often do you expect to run something on your machine and have people
from Wisconsin start getting the results of it on their screens?

All of this has raised some interesting points and problems.

1. Rwall will walk through your entire hosts file and blare at anyone
and everyone if you use the (,,) wildcard group. Whether this is a bug
or a feature, I don't know.

2. Since rwall is an RPC service, and RPC doesn't seem to give a damn
who you are as long as you're root (which is trivial to be, on a work-
station), I have to wonder what other RPC services are open holes. We've
managed to do some interesting, unauthorized, things with the YP service
here at Berkeley, I wonder what the implications of this are.

3. Having a group called "broadcast" in your netgroup file (which is how
it comes from sun) is just begging for some novice admin (or operator
with root) to use it in the mistaken belief that he/she is getting to
all the users. I am really surprised (as are many others) that this has
taken this long to happen.

4. Killing rwall is not going to solve the problem. Any fool can write
rwall, and just about any fool can get root priviledge on a Sun workstation.
It seems that the place to fix the problem is on the receiving ends. The
only other alternative would be to tighten up all the IMP gateways to
forward packets only from "trusted" hosts. I don't like that at all,
from a standpoint of reduced convenience and productivity. Also, since
many places are adding hosts at a phenominal rate (ourselves especially),
it would be hard to keep such a database up to date. Many perfectly well-
behaved people would suffer for the potential sins of a few.

I certainly don't intend to do this again, but I'm very curious as to
what will happen as a result. A lot of people got wall'd, and I would think
that they would be annoyed that their machine would let someone from the
opposite side of the continent do such a thing!

Jordan Hubbard
jkh@violet.berkeley.edu (ucbvax!jkh)
Computer Facilities & Communications.
U.C. Berkeley

From: Milo S. Medin <medin@orion.arpa>
Date: Apr 6, 1987, 5:06 AM

Actually, Dennis Perry is the head of DARPA/IPTO, not a pencil pusher
in the IG's office. IPTO is the part of DARPA that deals with all
CS issues (including funding for ARPANET, BSD, MACH, SDINET, etc...).
Calling him part of the IG's office on the TCP/IP list probably didn't
win you any favors. Coincidentally I was at a meeting at the Pentagon
last Thursday that Dennis was at, along with Mike Corrigan (the man
at DoD/OSD responsible for all of DDN), and a couple other such types
discussing Internet management issues, when your little incident
came up. Dennis was absolutely livid, and I recall him saying something
about shutting off UCB's PSN ports if this happened again. There were
also reports about the DCA management types really putting on the heat
about turning on Mailbridge filtering now and not after the buttergates
are deployed. I don't know if Mike St. Johns and company can hold them
off much longer. Sigh... Mike Corrigan mentioned that this was the sort
of thing that gets networks shut off. You really pissed off the wrong
people with this move!

Dennis also called up some VP at SUN and demanded this hole
be patched in the next release. People generally pay attention
to such people.

Milo

From: Mark Crispin <MRC%PANDA@sumex-aim.stanford.edu>
Date: Mon, Apr 6, 1987, 10:15 AM

Dan -

I'm afraid you (and I, and any of the other old-timers who
care about security) are banging your head against a brick wall.
The philsophy behind Unix largely seems quite reminiscent of the
old ITS philsophy of "security through obscurity;" we must
entrust our systems and data to a open-ended set of youthful
hackers (the current term is "gurus") who have mastered the
arcane knowledge.

The problem is further exacerbated by the multitude of slimy
vendors who sell Unix boxes without sources and without an
efficient means of dealing with security problems as they
develop.

I don't see any relief, however. There are a lot of
politics involved here. Some individuals would rather muzzle
knowledge of Unix security problems and their fixes than see them
fixed. I feel it is *criminal* to have this attitude on the DDN,
since our national security in wartime might ultimately depend
upon it. If there is such a breach, those individuals will be
better off if the Russians win the war, because if not there will
be a Court of Inquiry to answer...

It may be necessary to take matters into our own hands, as
you did once before. I am seriously considering offering a cash
reward for the first discoverer of a Unix security bug, provided
that the bug is thoroughly documented (with both cause and fix).
There would be a sliding cash scale based on how devastating the
bug is and how many vendors' systems it affects. My intention
would be to propagate the knowledge as widely as possible with
the express intension of getting these bugs FIXED everywhere.

Knowledge is power, and it properly belongs in the hands of
system administrators and system programmers. It should NOT be
the exclusive province of "gurus" who have a vested interest in
keeping such details secret.

-- Mark --

PS: Crispin's definition of a "somewhat secure operating system":
A "somewhat secure operating system" is one that, given an
intelligent system management that does not commit a blunder that
compromises security, would withstand an attack by one of its
architects for at least an hour.

Crispin's definition of a "moderately secure operating system": a
"moderately secure operating system" is one that would withstand
an attack by one of its architects for at least an hour even if
the management of the system are total idiots who make every
mistake in the book.
-------

From: Dennis G. Perry <PERRY@vax.darpa.mil>
Date: Apr 6, 1987, 3:19 PM

Jordan, you are right in your assumptions that people will get annoyed
that what happened was allowed to happen.

By the way, I am the program manager of the Arpanet in the Information
Science and Technology Office of DARPA, located in Roslin (Arlington), not
the Pentagon.

I would like suggestions as to what you, or anyone else, think should be
done to prevent such occurances in the furture. There are many drastic
choices one could make. Is there a reasonable one? Perhaps some one
from Sun could volunteer what there action will be in light of this
revelation. I certainly hope that the community can come up with a good
solution, because I know that when the problem gets solved from the top
the solutions will reflect their concerns.

Think about this situation and I think you will all agree that this is
a serious problem that could cripple the Arpanet and anyother net that
lets things like this happen without control.

dennis
-------

Also:

http://catless.ncl.ac.uk/Risks/4.73.html#subj10.1

https://everything2.com/title/Jordan+K.+Hubbard