El Tue, Nov 11, 2008 at 11:28:03PM +0530 Vimal ha dit:
> >>>
> >>> the sysadmin sets LD_PRELOAD to /lib/libunlinkwrapper.so which
> >>> overrides the unlink() system call to add logging.
> >>>
> >>> now a nasty user wants to delete a file using unlink() (though she
> >>> could use others to change the content of the file) without being
> >>> traced by the sysadmin. to achieve this she could execute:
> >>> LD_PRELOAD= rm <important_file>
>
> Can pre-loading such object files to override system calls (I think
> it's called library interspersing or something...) be done on
> executables with setuid bit set? (example: ping/su, etc...)
from man ld.so(8):
For setuid/setgid ELF binaries, only libraries in the standard search
directories that are also setgid will be loaded
--
Matthias Kaehlcke
Embedded Linux Engineer
Barcelona
La posibilidad de realizar un suenyo es lo
que hace que la vida sea interesante
.''`.
using free software / Debian GNU/Linux | http://debian.org : :' :
`. `'`
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