Re: OT? Are chroots immune to buffer overflows?

From: KF (dotslashat_private)
Date: Tue May 21 2002 - 22:23:13 PDT

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

    I thought you just did something like the following in your shellcode...
    
    setuid(0)
    mkdir("blah")
    chroot("blah")
    chroot("../../../../../../../../../../../../")
    execve("/bin/sh",0,0)
    
    -KF
    
    Kalle Andersson wrote:
    
    >Of course can buffer overflows  be done with success, but it will be
    >much more difficult.
    >
    >Remember, if you are root inside a chroot-jail you are root on the
    >machine. You can probably someway trick the server into downloading
    >necessary code and files to remount the filesystems into the
    >chroot-environment or make connections to other trusted servers etc
    >etc....
    >
    >FreeBSD Jails are somewhat more secure, you might want to look into
    >that.
    >
    >
    >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.
    >>
    >>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
    >>
    >
    >--
    >Best Regards
    >Kalle Andersson
    >Technical Manager / EuroTrust Sweden AB
    >kanat_private
    >
    >
    



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