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>
Published: 2020-10-16
Score: 7.1 High
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories
Source ID Title
EUVD EUVD EUVD-2020-8927 <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>
History

Mon, 23 Feb 2026 18:15:00 +0000

Type Values Removed Values Added
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> <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>

Wed, 16 Jul 2025 13:45:00 +0000

Type Values Removed Values Added
Metrics epss

{'score': 0.01181}

epss

{'score': 0.01608}


Subscriptions

Microsoft Exchange Server
cve-icon MITRE

Status: PUBLISHED

Assigner: microsoft

Published:

Updated: 2024-08-04T13:45:34.738Z

Reserved: 2020-08-04T00:00:00.000Z

Link: CVE-2020-16969

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Modified

Published: 2020-10-16T23:15:16.743

Modified: 2026-02-23T18:21:34.873

Link: CVE-2020-16969

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses