Re: OT? Are chroots immune to buffer overflows?

From: Berend De Schouwer (bdsat_private)
Date: Wed May 22 2002 - 00:03:53 PDT

  • Next message: dev-null@no-id.com: "Re: OT? Are chroots immune to buffer overflows?"

    On Wed, 2002-05-22 at 05:48, Jason Haar wrote:
    > [note: my question is WRT non-root chrooted jails - we all know about
    > chroot'ing root processes!]
    > 
    > Most buffer overflows I've seen attempt to infiltrate the system enough to
    > run /bin/sh. In chroot'ed environments, /bin/sh doesn't (shouldn't!) exist -
    > so they fail.
    
    I've had someone try /usr/X11R6/bin/xterm!  (no, there wasn't an xterm
    either :)
    > 
    > Is it as simple as that? As 99.999% of the system binaries aren't available
    > in the jail, can a buffer overflow ever work?
    
    Yes -- just append a binary /bin/sh to the end of the buffer overflow,
    and run that instead of exec("/bin/sh").  Try with a statically linked
    one first.
    > 
    > -- 
    > Cheers
    > 
    > Jason Haar
    > 
    > Information Security Manager
    > Trimble Navigation Ltd.
    > Phone: +64 3 9635 377 Fax: +64 3 9635 417
    -- 
    Berend De Schouwer
    



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