Quote from: krishnapramod on October 02, 2015, 07:19:02 AM

I thought Funcaptcha is the best option against bots, but today I found a major flaw in Funcaptcha. In a normal Funcaptcha a user has to solve two or three images (moving the woman to center or rotating it to correct position) to claim. An hour ago I visited a faucet with Funcaptcha, I accidentally clicked the claim button just after solving one image and the claim was credited. I tried this on a couple of more faucets and the same result.

So basically you just need to solve 1 Funcaptcha image to claim

I visited a faucet with advanced Funcaptcha option (6 images to solve), but on this faucet I was not able to claim after solving one image which is good.

I believe Funcaptcha does prevent bot abuse, but solving just one image might make it a bit vulnerable.

Opting for advanced option might be annoying to users. Solving three images is more than enough, but Funcaptcha developers have to make sure the captcha is not validated till three images are confirmed

Hi krishnapramod,

The short answer is that FunCaptcha can vary from 1 to 5 challenges depending on the settings chosen by the website (the faucet) and the past history of the user. So, sometimes you have to pick the woman once, sometimes three times, sometimes five times before you can claim. When you've done enough challenges, the footer under FunCaptcha tells you that you're done. More is explained here:
http://support.funcaptcha.com/customer/en/portal/articles/1838700-why-do-i-sometimes-need-to-do-more-or-fewer-game-challenges-

A site can pick the "always enhanced" setting in their FunCaptcha dashboard to make sure the number of challenges never falls below 3. You also can contact us for even more advanced settings if you think you see bots getting through. We give a wide range of settings which at one extreme are always very easy for all users to complete fast, and at the other extreme are the very strongest protection against bots. We adjust it automatically for a site, but the site can request a different setting.

What you experienced was FC's setting in which you can solve just one image to pass. You must have at one point seen FunCaptcha with three challenges, then solved it, which improved your user history enough for FC to give you just one challenge the next time.

To experiment with this, come to https://www.funcaptcha.com/demo/ and try getting FC right a few times in a row, then wrong a few times in a row. You will see how the number of challenges goes as low as one or as high as five.

Last point: if FunCaptcha asks you to rotate a LOGO the right way up, instead of an animal, or to pick "your favourite", it does not matter how you answer. This is done on purpose for a few obscure reasons and never is counted as one of the challenges.

I hope this helps, and thanks for starting the discussion.

Matt
FunCaptcha creator