Cryptolocker (was RE: Is tape dead?

Paul Koning paulkoning at
Wed Sep 16 13:29:50 CDT 2015

> On Sep 16, 2015, at 2:10 PM, Chuck Guzis <cclist at> wrote:
> This brings up something that's always baffled me.
> Why does a user's (or worse, the entire system's) files have to be immediately accessible to any application wanting to take a look.
> Take a legacy example, SCOPE or NOS on a CDC mainframe.  ...

Just remember that those older systems may well have had any number of security issues of their own.  They did benefit a lot from "security by obscurity" as well as the fact that they weren't connected to the Internet.

I never had any incentive to look for holes in CDC operating systems, but I still remember a simple hole I found in OS/360, about a month after I first wrote a program for that OS.  It allowed anyone to run supervisor mode code with a couple dozen lines of assembler source code. I found it on OS/PCP 19.6, but I noticed in graduate school that it still worked on the university's 370 running OS/MVS 21.7.

(The magic?  Use the OS service to give a symbolic name to a location in your code, with a well chosen name, then give that name as the name of the "start I/O appendage" in an EXCP style I/O request.)


More information about the cctalk mailing list