Collected research

Firefox Popup Blocker Allows Reading Arbitrary Local Files

SecuriTeam™ - Firefox Popup Blocker Allows Reading Arbitrary Local Files

Michal Zalewski · securiteam.com

Zalewski's chain for reading local files from the web in Firefox 1.5.0.9. Manually unblocking a popup skips the URL permission check, and file:// documents are mutually same-origin, so a planted local HTML file can XMLHttpRequest other files and post them out.

Record

Document

SecuriTeam™ - Firefox Popup Blocker Allows Reading Arbitrary Local Files

Researcher

Michal Zalewski

Published by

securiteam.com

Topic

Browser

In the archive

• Collected in the 2007 research round

Tags

• sop-bypass
• same-origin-policy
• info-leak
• javascript
• filter-bypass
• owasp-a01-2021
• owasp-a05-2021

This page is the archive's own catalogue record. The research is the work of Michal Zalewski, first published at the original source. Preserved copies are kept so the citation survives its host; this one was last captured on 14 August 2026.