Web Hack List

Collected research

Bruteforcing HTTP Auth in Firefox with JavaScript

Firefox fetches favicons and rel=prefetch targets without prompting for HTTP auth, so a page can silently probe protected resources. Esser turns that into a password oracle: a shortcut-icon link carrying user:pass@URL primes Firefox's favicon cache, then an img against the same credentialed URL fires onLoad or onError to report whether the guess was right. expose_php GUIDs supply a target.

Record

Researcher
Stefan Esser
Published by
blog.php-security.org
Topic
HTTP

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