[FLEX-35123] DOM XSS vulnerability in history.js

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: Apache Flex 4.16.0
• Flags: Patch
• Assignee: Justin Mclean
• Reporter: Aron Nopanen
• Created: 26/Aug/16 19:35
• Updated: 03/Nov/16 18:51
• Resolved: 03/Nov/16 06:46

Description

Template file history.js contains a DOM XSS vulnerability. While it looks like it would be difficult to exploit, it should be addressed.

The code in question is in a block specific to ancient versions of Safari (<= 2.0.4), so I propose that block could safely be removed entirely.

The vulnerable line is:

getFormElement().innerHTML = '<form name="historyForm" action="'file'#' + flexAppUrl + '" method="GET"></form>';

The variables 'file' and 'flexAppUrl' are being passed unescaped into HTML subcontext.

I'm attaching a patch that would remove the Safari-specific handling, including the vulnerable line.