Top 10 winner

Web Mayhem: Firefox's JAR: Protocol issues

Web Mayhem: Firefox’s JAR: Protocol issues

pdp · GNUCITIZEN · 7 November 2007

Firefox's jar: protocol runs content from inside an archive under the origin of the archive's URL, so any site accepting ZIP-derived uploads (odt, docx, attachments) becomes vulnerable to persistent XSS. pdp also notes jar: can be nested and can wrap data:, letting a payload be obfuscated past antivirus and IDS.

Record

Document

Web Mayhem: Firefox’s JAR: Protocol issues

Researcher

pdp

Published by

GNUCITIZEN

Date

7 November 2007

Topic

Browser

In the archive

• Ranked #3 in the 2007 Top 10 Web Hacking Techniques

Related sources

• Bug 369814 — jar: protocol is an XSS hazard due to ignoring mime type and being considered same-origin with hosting site

Tags

• xss
• file-upload
• sop-bypass
• same-origin-policy
• mime
• filter-bypass
• owasp-a01-2021
• owasp-a03-2021
• owasp-a05-2021

This page is the archive's own catalogue record. The research is the work of pdp, first published at the original source. Preserved copies are kept so the citation survives its host; this one was last captured on 10 September 2026.