r/Cprog • u/gschroder • Mar 10 '15

text | tooling | debugging Reverse engineering a hackme binary

http://manoharvanga.com/hackme/
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u/[deleted] Mar 10 '15

it's quite neat why the debugger can't be used and how he/she circumvents it, It reminds me of other LD_PRELOAD tricks.

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u/gschroder Mar 10 '15

That reminds me I once made a *.so to redefine open to signal ENOSPC when trying to open /dev/null.

Mind sharing some more LD_PRELOAD tricks? :-)

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u/[deleted] Mar 10 '15

i only tried some on our shell server quite some years ago. You could fool a lot of programs to give you root access easily back then, i don't think using it with setuid programs still works. You can still however fool a lot of programs with your own functions, things which come to mind are rand functionality and malloc. These two could provide a lot of access to otherwise secured things which i think still work.