progs/README
author Christian Urban <christian dot urban at kcl dot ac dot uk>
Mon, 16 Nov 2015 13:20:24 +0000
changeset 431 4b53f83c070c
parent 410 d0a95f3aa65e
child 467 da4896f201b5
permissions -rw-r--r--
updated
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
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Virtual-Box
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Start "Linux Hacking"   
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  login is cu
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  password is "test"
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The programs are under 
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  cu$> app-material/progs
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Programs can be updated using
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  hg pull
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  hg update
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  hg revert --all
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Emacs can be used to edit files
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  emacs -nw ...file....     (is also an alias)
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C0.c
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====
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Add the bigger string and the long is printed out differently.
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402
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foo("my string is too long !!!!! \x15\xcd\x5b\x07");
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C1.c
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====
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needs to be called using
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  ./C1 `args1-good`
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  ./C1 `args1-bad`
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or in gdb using
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  gdb --args ./C1 `args1-bad`
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C2.c
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====
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called with
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  ./args2-good | ./C2
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  ./args2-bad  | ./C2
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C3.c
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====
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(shell injection)
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called with 
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  ./C3
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opens a new shell
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C4.c
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====
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Format string attack
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  ./C4 "%s"
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  ./C4 `./args4`
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403
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This vulnerability does not need the defences, but prints out
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the string only correctly with `./args4`. The %s option needs
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  -mpreferred-stack-boundary=2
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------------------------------------
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to switch off address randomization
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echo 0 | sudo tee /proc/sys/kernel/randomize_va_space
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C0.c
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add to string 
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  " \x15\xcd\x5b\x07"
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to get
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  foo("my string is too long !!!!! \x15\xcd\x5b\x07");