Web Hack List

Collected research

reCAPTCHA bypass via HTTP Parameter Pollution

Applications that build the reCAPTCHA siteverify URL by string concatenation let an attacker smuggle a second secret parameter through the response field. Because the API honoured the first secret, supplying Google's documented always-pass test key made every verification return success, defeating the CAPTCHA entirely.

Record

Published by
Andres Riancho
Topic
HTTP

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This page is the archive's own catalogue record. The research is the work of Andres Riancho, first published at the original source. Preserved copies are kept so the citation survives its host; this one was last captured on .