CWE-804 Detail

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.

Modes Of Introduction

Architecture and Design
Implementation

Applicable Platforms

Language

Class: Not Language-Specific (Undetermined)

Technologies

Name: Web Server (Sometimes)

Common Consequences

Observed Examples

Vulnerability Mapping Notes

Justification : This CWE entry is at the Base level of abstraction, which is a preferred level of abstraction for mapping to the root causes of vulnerabilities.
Comment : Carefully read both the name and description to ensure that this mapping is an appropriate fit. Do not try to 'force' a mapping to a lower-level Base/Variant simply to comply with this preferred level of abstraction.

References

REF-731

Insufficient Anti-automation
Web Application Security Consortium.
http://projects.webappsec.org/Insufficient+Anti-automation

Submission

Modifications