Captcha Bypass

Captcha Bypass

To automate the testing of some functions of the server that allows user input it could be needed to bypass a captcha implementation. Test these things:

• Do not send the parameter related to the captcha.

  • Change from POST to GET or other HTTP Verbs

  • Change to JSON or from JSON

• Send the captcha parameter empty.

• Check if the value of the captcha is in the source code of the page.

• Check if the value is inside a cookie.

• Try to use an old captcha value

• Check if you can use the same captcha value several times with the same or different sessionID.

• If the captcha consists on a mathematical operation try to automate the calculation.

• If the captcha consists on read characters from an image, check manually or with code how many images are being used and if only a few images are being used, detect them by MD5.

• Use an OCR (https://github.com/tesseract-ocr/tesseract).