Yahoo CAPTCHAs might not be strong enough

A follow up on Are CAPTCHAs broken for good?

Russian security researchers tested the strength of CAPTCHA used by Yahoo:

Few months ago we received information that yahoo CAPTCHA recognition system exists in the wild with the recognition rate about 30%. So we decided to conduct few experiments. We explored yahoo CAPTCHA and designed a similar system with even better recognition rate (about 35%). The vendor was notified. The vendor didn't reply. In this article we’ll present you our own research.

Full article.

Previous CAPTCHA articles.