Vulnerability · Published Oct 16, 2020 · Assigned by microsoft
CVE-2020-16969Microsoft Exchange Information Disclosure Vulnerability
High 7.1
In plain English
A high-severity security flaw in Microsoft Exchange Server 2013 Cumulative Update 23 from Microsoft. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 2.7% (higher than 86% of all known vulnerabilities).
Official description
<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 (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Microsoft | Microsoft Exchange Server 2019 Cumulative Update 6 | 15.02.0 – before publication |
| Microsoft | Microsoft Exchange Server 2016 Cumulative Update 17 | 15.01.0 – before publication |
| Microsoft | Microsoft Exchange Server 2019 Cumulative Update 7 | 15.02.0 – before publication |
| Microsoft | Microsoft Exchange Server 2016 Cumulative Update 18 | 15.01.0 – before publication |
| Microsoft | Microsoft Exchange Server 2013 Cumulative Update 23 | 15.00.0 – before publication |