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-
- How to Crash GBBS Systems
-
-
-
- The following is a text file theat
- I downloaded from the O.S.B. Systems
- In Allentown. I think it is a very
- interesting file for all to look over
- see what we can use for our own systems
- After all that is what this SysOp board
- is all about, keeping the undesirables
- away and discouraging the crashers.
- -Nonsuch-
-
-
- <><><><><><><><><><><><><><><><><><><>
- ><> CRASH PROTECTING YOUR GBBS II! <><
- <><><><><><><><><><><><><><><><><><><>
- by init hello
-
-
- Let's dispense with formalites at go
- directly to the matter at hand. This
- tutuorial will outline the ways in
- which a GBBS II can be crashed and
- offer solutions. If all directions are
- followed, then your board will be
- impervious to user interference.
-
- (A) the most common and most elemen-
- tary methods is by what is commonly
- refered to as "the old space trick".
- What is done is a person enters as a
- "NEW" user and uses the sysop's name
- with a space before the first name.
- This bypasses all the "NAME IN USE"
- checks but awards a sysop security of
- 64 upon entry. The simple remedy would
- be to not allow spaces in a name that
- aren't imbedded. For example:
-
- 510 O$=EL$+"LAST NAME-->":GOSUB
- 7000:GOSUB8200:A2$=I$...ETC.
- add the
- line:515 IF LEFT$(I$,1)=" " THEN 510
-
-
- this should be also entered on a
- line after the FIRST name is inputted.
-
-
- (B) Another common method is taking
- advantage of the sysop's mods, namely,
- onerr goto statements. What a person
- can do is purposely make an error to
- get him to where the onerr goto state-
- ment is pointing. This might be an area
- that the user does NOT have access to.
- To prevent this, nullify all your onerr
- goto statements after you're done with
- them with a "POKE 216,0". When the
- onerr flag is reset with this statement
- all errors will result in a prompt log-
- off.
- Common methods of creating errors
- are:
- 1) when the program asks for a
- number, entering a "99E99".
-
- 2) when asking for a password,
- entering a negative number
- imbedded in the letters.
- (ie. G-99FFF, OR A-01AAA )
-
- 3) then there are the fatal
- errors that will be covered in
- section C.
-
-
- (C) Here is the good part. The
- GBBS II driver ignores the entry of all
- characters with an ascii equivalent of
- hexadecimal ($20) and below, EXEPT....
- a big EXCEPT...for a few!! Now these
- few characters when entered, goes
- unnoticed....that is...unless enough
- of the are entered. If a sufficient
- number is entered,(which would take a
- long time without a repeat key), then
- the buffer suffers what I call a
- "FATAL ERROR" which will promptly put
- the user into machine language with
- DOS intact. Oh noooooooo!! But there is
- good, news! If the following pokes are
- entered directly after the GBBS DRIVER
- is loaded, let's say on line 60, then
- it will treat those certain characters
- like all the rest of the trash and
- ignore them!!
-
- 60 POKE 36942,37:
- POKE 36943,208:
- POKE 36944,35:
- POKE 36945,76:
- POKE 36946,95:
- POKE 36947,255:
- POKE 36948,234
-
- And that's it! All of the above has
- been carefully tested and retested so
- the informatin is valid. This tutorial
- has been written in a way to discourage
- those seeking ways to crash people's
- boards as well as possible.
-
- [0;_[0m
- [1m[8] Tfiles: (1-29,?,Q) :
-
-