CVE-2021-33766: Microsoft Exchange Server Information Disclosure

Published Jul 13, 2021
·
Updated

Microsoft Exchange Information Disclosure Vulnerability

Other sources

Microsoft Exchange Server contains an information disclosure vulnerability which can allow an unauthenticated attacker to steal email traffic from target.

CISA

Microsoft Exchange Server Information Disclosure Vulnerability

Microsoft

Affected Software

12 affected componentsFixes available
Microsoft Exchange Server
Microsoft Exchange Server=2013-cumulative_update_23
Microsoft Exchange Server=2016-cumulative_update_19
Microsoft Exchange Server=2016-cumulative_update_20
Microsoft Exchange Server=2019-cumulative_update_8
Microsoft Exchange Server=2019-cumulative_update_9
Microsoft Exchange
Microsoft Exchange Server 2019=8
15.02.0792.013
Microsoft Exchange Server 2016=19
15.01.2176.012
Microsoft Exchange Server 2016=20
15.01.2242.008
Microsoft Exchange Server 2019=9
15.02.0858.010
Microsoft Exchange Server 2013=23
15.00.1497.015

Event History

Jul 13, 2021
CVE Published
via Microsoft·02:00 PM
Data Sourced
via Microsoft·02:00 PM
DescriptionSeverityWeaknessAffected Software
Updated
via Microsoft·02:00 PM
Affected Software
Updated
via Microsoft·02:00 PM
Description
Jul 14, 2021
CVE Published
via MITRE·05:53 PM
Data Sourced
via MITRE·05:53 PM
DescriptionSeverity
Data Sourced
via NVD·06:15 PM
RemedyDescriptionSeverityAffected Software
Jul 15, 2021
Advisory Published
via ZDI·12:00 AM
Data Sourced
via ZDI·12:00 AM
DescriptionSeverityAffected Software
Jan 18, 2022
Known Exploited
via CISA·12:00 AM
Free Weekly Intel

Don't miss critical vulnerabilities

Join thousands of security professionals who receive our weekly digest of trending CVEs, zero-days, and exploited vulnerabilities.

No spam. Unsubscribe anytime.

Frequently Asked Questions

1

What is CVE-2021-33766?

CVE-2021-33766 is a vulnerability that allows remote attackers to disclose sensitive information on affected installations of Microsoft Exchange Server.

2

How severe is CVE-2021-33766?

CVE-2021-33766 has a severity rating of 7.5, which is considered high.

3

What software is affected by CVE-2021-33766?

Microsoft Exchange Server 2013, 2016, and 2019 are affected by CVE-2021-33766.

4

Do I need authentication to exploit CVE-2021-33766?

No, authentication is not required to exploit CVE-2021-33766.

5

How can I fix CVE-2021-33766?

To fix CVE-2021-33766, apply the relevant patches provided by Microsoft or follow the recommended remediation steps available on their support website.

Contact

SecAlerts Pty Ltd.
132 Wickham Terrace
Fortitude Valley,
QLD 4006, Australia
info@secalerts.co
By using SecAlerts services, you agree to our services end-user license agreement. This website is safeguarded by reCAPTCHA and governed by the Google Privacy Policy and Terms of Service. All names, logos, and brands of products are owned by their respective owners, and any usage of these names, logos, and brands for identification purposes only does not imply endorsement. If you possess any content that requires removal, please get in touch with us.
© 2026 SecAlerts Pty Ltd.
ABN: 70 645 966 203, ACN: 645 966 203