Microsoft Corporation AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L

An information disclosure vulnerability exists in how Microsoft Exchange validates tokens when handling certain messages, aka 'Microsoft Exchange Information Disclosure Vulnerability'.

<p>An information disclosure vulnerability exists in how Microsoft Exchange validates tokens when handling certain messages. An attacker who successfully exploited the vulnerability could use this to gain further information from a user.</p>
<p>To exploit the vulnerability, an attacker could include specially crafted OWA messages that could be loaded, without warning or filtering, from the attacker-controlled URL. This callback vector provides an information disclosure tactic used in web beacons and other types of tracking systems.</p>
<p>The security update corrects the way that Exchange handles these token validations.</p>