Software Engineering Institute

Web browsers that allow remote web sites to reference content that resides on the local filesystem may be vulnerable to cross-domain security violations. In a typical attack scenario, an attacker must first place content in a known or predictable location on a computer. If a web browser allows a remote web site to reference that content, this may allow attacker-supplied script to run within the security context of the local machine.

Web browsers based on AppleWebKit, such as Safari, fail to restrict web sites from accessing content on the local filesystem. OmniWeb, which is based on Apple WebCore, also contains the same vulnerability. Current proof-of-concept exploit code uses the XMLHttpRequest object to read files from the local filesystem.

A remote, unauthenticated attacker may be able to execute script within the security context of the local machine. Script that executes within this context may be able to perform privileged actions, such as reading files from the local filesystem. These actions would not be possible by using script that executes within the security context of the remote web site.

Upgrade or patch
Please see the Systems Affected section of this document for update availability.

Workarounds

Users who are unable to upgrade to a fixed version of the software are encouraged to disable JavaScript in their browsers.