CVE-2020-16969
<p>An information disclosure vulnerability exists in how Microsoft Exchange validates tokens when handling certain messages.
Impact
<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>
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Microsoft | Exchange Server | Versions 2013, 2016, 2019 |