High severity · published Jul 14, 2021
CVE-2021-33766
Microsoft Exchange Server Information Disclosure Vulnerability
In wildKEV
7.3
CVSS
98.2%
EPSS
Yes
On KEV
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
Low
Integrity
Low
Availability
Low
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)98.2% · higher than 100% of CVEs
Exploited in the wildYes
CISA KEVListed Jan 18, 2022
Federal remediation dueFeb 1, 2022
Ransomware campaign useNot known
Affected products
Which versions
ES
Exchange Server · Microsoft
2013; 2016; 2016; 2019; 2019 · source: NVD, KEV
ME
Microsoft Exchange Server 2013 Cumulative Update 23 · Microsoft
15.00.0 before 15.00.1497.015 · source: vendor
ME
Microsoft Exchange Server 2016 Cumulative Update 19 · Microsoft
15.01.0 before 15.01.2176.012 · source: vendor
ME
Microsoft Exchange Server 2016 Cumulative Update 20 · Microsoft
15.01.0 before 15.01.2242.008 · source: vendor
ME
Microsoft Exchange Server 2019 Cumulative Update 8 · Microsoft
15.02.0 before 15.02.0792.013 · source: vendor
ME
Microsoft Exchange Server 2019 Cumulative Update 9 · Microsoft
15.02.0 before 15.02.0858.010 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-33766
CVE.org
https://www.cve.org/CVERecord?id=CVE-2021-33766
CISA KEV catalogue
https://www.cisa.gov/known-exploited-vulnerabilities-catalog
vendor-advisory
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-33766
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