On Tue, 23 May 2000 03:13:33 +0200, Jacob Palme <[EMAIL PROTECTED]>  said:
> That would mean that every time you execute any program, you would
> have to get an analysis of its possible harmful effects and decide
> whether to accept it. Possibly, the system could be designed so
> that a checksum is stored with every executable program, and you
> do not have to answer this question if the checksum has not
> changed since the last time you executed the same program.

This idea isn't as secure as it seems.  For any given useful
program 'foobar' that you are invoking again, you probably have
different input data (otherwise, why are you bothering running
it again to get the same result as last time? ;)

Remember that in 98% of the now-boring 'Yet Another Buffer Overflow'
cases, the checksum and permitted actions for the program were
unchanged, had been unchanged for possibly YEARS - but the program
coughs up a hairball when stressed with different input data.

                                Valdis Kletnieks
                                Operating Systems Analyst
                                Virginia Tech

Reply via email to