Vulnerability Development: Re: Behavior analysis vs. Integrity analysis [was: Binary Bruteforcing]

["auto12012 auto12012" <auto12012 () hotmail com>]

> >
> > Most likely been done already. In the 70's. At the time when information
> > security was a science.
>
> No. That is not what I meant. To tell whether ftp daemon is working well
> or not, you have to know what behavior is appropriate for ftp daemon, and
> what is not. If FTP daemon can be fooled, without actually inserting
> malicious code, to, say, change root's password, this is a vulnerability,
> but it does not mean it exhibits some universal "vulnerability pattern" -
> it just went off the track and jumped into another, perfectly valid for,
> say, passwd utility. So what I am referring to are functional
> specifications for this particular application, so all possible behavioral
> tracks of the actual code can be compared to what we expect it to do. This
> is expensive, lengthy and prone to design errors.
>
> And again, I do not buy the argument that there's one fixed, static point
> that does not depend on the execution path that can be considered a point
> of vulnerability. No.
That is too bad. If you fail to understand that ftp daemon, in your example, 
is not vulnerable because it adopts a behavior that it is not excepted to 
follow, but simply because it compromises the integrity of an object (root 
password), with the lower integrity of the subject (non-root user), then I 
am disapointed. If I do not believe vulnerability is related to execution 
path, it is not because I believe it is not dependent of anything, but 
simply because I believe it is dependent of something that is of much higher 
abstraction: logic.
> --
> _____________________________________________________
> Michal Zalewski [lcamtuf () bos bindview com] [security]
> [http://lcamtuf.coredump.cx] <=-=> bash$ :(){ :|:&};:
> =-=> Did you know that clones never use mirrors? <=-=
>           http://lcamtuf.coredump.cx/photo/

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