Guessable CAPTCHA

The product uses a CAPTCHA challenge, but the challenge can be guessed or automatically recognized by a non-human actor.

An automated attacker could bypass the intended protection of the CAPTCHA challenge and perform actions at a higher frequency than humanly possible, such as launching spam attacks.

There can be several different causes of a guessable CAPTCHA:

• An audio or visual image that does not have sufficient distortion from the unobfuscated source image.
• A question is generated with a format that can be automatically recognized, such as a math question.
• A question for which the number of possible answers is limited, such as birth years or favorite sports teams.
• A general-knowledge or trivia question for which the answer can be accessed using a data base, such as country capitals or popular entertainers.
• Other data associated with the CAPTCHA may provide hints about its contents, such as an image whose filename contains the word that is used in the CAPTCHA.