Windows Media Player version 11 suffers from a local file detection vulnerability.
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*** Windows Media Player Plugin: Local File Detection Vulnerability ***
A design flaw in Windows Media Player 11 allows a remote attacker to determine the presence of local files (programs, documents, etc.). I sent an e-mail to Microsoft (nearly a year ago) but they never responded
Windows Media Player permits to open locally stored media-files. Opening non-supported files usually provokes an error message. By a simple HTTP-redirect, the error message can be circumvented. Local files can be opened. The file-opening-procedure can be controlled with the Player.OpenStateChange Event. If a file exists, event 8 (MediaChanging) is fired. This way, via JavaScript, a malicious web site could determine the presence of local (and remote) files.
Additional infos (in German): www.lrv.ch.vu
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