Security researcher Armin Razmdjou reported that a user readable file in a known local path could be uploaded to a malicious site. This was done by manipulating the autocomplete feature in a form and user interaction with it. While the local file is not visibly uploaded through the form, its contents are made available through the Document Object Model (DOM) to script content on the attacking page, leading to information disclosure.

In general this flaw cannot be exploited through email in the Thunderbird product because scripting is disabled, but is potentially a risk in browser or browser-like contexts.



External Reference:

https://www.mozilla.org/en-US/security/advisories/mfsa2015-24


Acknowledgements:

Red Hat would like to thank the Mozilla project for reporting this issue. Upstream acknowledges Armin Razmdjou as the original reporter.