Re: fixing all buffer overflows --- random magin numbers

From: Oliver Xymoron (oxymoronat_private)
Date: Fri Sep 17 1999 - 09:06:38 PDT

  • Next message: Tymm Twillman: "A few bugs..."

    On Tue, 14 Sep 1999, Crispin Cowan wrote:
    
    > (post sent as HTML and ASCII because there's a table that's easier to read
    > in HTML.  Aleph, go ahead and nuke the HTML if you prefer)
    
    Urg. Pine happily munged it on reply:
    
    > The result looks like this:
    >
    >             Interface                            Implementation
    >
    >  Restriction   * Firewalls                          * Bounds checking
    >                * TCP Wrappers                       * StackGuard
    >                * Randomly renaming system files
    >                * Randomly renumbering system
    >  Permutation     calls (the hack proposed here      * Randomly munging
    >                  by Maniscalco)                       data layout
    >                * Fred Cohen's Deception Toolkit
    
    You missed a couple interesting ones. One is randomly offsetting the
    stack. Another is having separate stacks for the call chain and local
    variables. Obviously wastes a register (or an indirection), but can
    probably be proved secure against stack smashing.
    
    --
     "Love the dolphins," she advised him. "Write by W.A.S.T.E.."
    



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