Medium severity · published May 11, 2021
CVE-2021-31207
Microsoft Exchange Server Security Feature Bypass Vulnerability
RansomwareIn wildKEV
6.6
CVSS
99.8%
EPSS
Yes
On KEV
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
High
Privileges
High
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)99.8% · higher than 100% of CVEs
Exploited in the wildYes
CISA KEVListed Nov 3, 2021
Federal remediation dueNov 17, 2021
Ransomware campaign useKnown
Affected products
Which versions
ES
Exchange Server · Microsoft
15.00.0 before 15.00.1497.018 · source: vendor, NVD, KEV
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-31207
CVE.org
https://www.cve.org/CVERecord?id=CVE-2021-31207
CISA KEV catalogue
https://www.cisa.gov/known-exploited-vulnerabilities-catalog
x_refsource_MISC
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-31207
x_refsource_MISC
https://www.zerodayinitiative.com/advisories/ZDI-21-819/
x_refsource_MISC
http://packetstormsecurity.com/files/163895/Microsoft-Exchange-ProxyShell-Remote-Code-Execution.html
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