7 Mar
2022
7 Mar
'22
11:16 p.m.
On Mar 7, 2022, at 3:56 PM, Thomas DeBellis
<tommytimesharing(a)gmail.com>
wrote:
What about other DEC multi-user operating systems? Do
you have 'magic'
consoles?
On VMS, at least older versions and I assume more recent versions are the
same, if the UAF (user authorization file) does not exist AND you try to
login in from OPA0 (the hardwired console terminal), then it will still ask
for a password but it will always log you in no matter what password you
give. If you do the same from any other terminal under the same conditions
the login will always fail.
This is one way (there are a couple) to break into a VMS system if you
have physical access to the console terminal. The usual procedure is to do
a conversational boot, set the UAFALTERNATE parameter to 1, and then finish
the boot. UAFALTERNATE tells the system to use the alternate, backup, UAF
file which typically doesn't exist and in that case you have the above
situation. Of course if you really do have an alternate UAF file then this
won't work and you'll have to go to plan B...
Bob