Release Date: 10/05/04
Affected Products: Safari =< 1.2
Fixed in: Not fixed.
Impact: Remote code execution.
Vendor: Notified (23/02/04)
Apple uses a special function to execute scripts and applications from his Help system. Unfortunatly, this Help system uses HTML format and is callable from within browsers such as Safari (all other browsers tested were vulnerables too).
The problem lies in the fact that Apple added a special function into his own HTML renderer called "runscript". A link to help:runscript can be triggered from the browsers and thus launching the desired application/script.
The desired application/script can be downloaded to a known location using Safari Safe Open File (default setting) by downloading a Disk Image (.dmg) which will always point to /Volume/DiskImageName/ScriptName. It is also possible to guess the user login when Safe Open File is disabled, and might be possible to include inline Apple Script commands without calling any external application.
This advisory was released since the bug has been made public recently. Apple is working on a fix which should be issued shortly.
To protect yourself:
- disable auto opening of safe files in Safari (bad protection, doesn't prevents anything really)
- change the help helper in InternetConfig (better protection)
Author link: http://fundisom.com/owned/warning
Proof of concept: