7.5

CVE-2021-26855

Warnung
Medienbericht
Exploit

Microsoft Exchange Server Remote Code Execution Vulnerability

Microsoft Exchange Server Remote Code Execution Vulnerability
Daten sind bereitgestellt durch National Vulnerability Database (NVD)
Microsoft ≫ Exchange Server Version 2013 Update cumulative_update_21
Microsoft ≫ Exchange Server Version 2013 Update cumulative_update_22
Microsoft ≫ Exchange Server Version 2013 Update cumulative_update_23
Microsoft ≫ Exchange Server Version 2016 Update cumulative_update_10
Microsoft ≫ Exchange Server Version 2016 Update cumulative_update_11
Microsoft ≫ Exchange Server Version 2016 Update cumulative_update_12
Microsoft ≫ Exchange Server Version 2016 Update cumulative_update_13
Microsoft ≫ Exchange Server Version 2016 Update cumulative_update_14
Microsoft ≫ Exchange Server Version 2016 Update cumulative_update_15
Microsoft ≫ Exchange Server Version 2016 Update cumulative_update_16
Microsoft ≫ Exchange Server Version 2016 Update cumulative_update_17
Microsoft ≫ Exchange Server Version 2016 Update cumulative_update_18
Microsoft ≫ Exchange Server Version 2016 Update cumulative_update_19
Microsoft ≫ Exchange Server Version 2016 Update cumulative_update_8
Microsoft ≫ Exchange Server Version 2016 Update cumulative_update_9
Microsoft ≫ Exchange Server Version 2019 Update -
Microsoft ≫ Exchange Server Version 2019 Update cumulative_update_1
Microsoft ≫ Exchange Server Version 2019 Update cumulative_update_2
Microsoft ≫ Exchange Server Version 2019 Update cumulative_update_3
Microsoft ≫ Exchange Server Version 2019 Update cumulative_update_4
Microsoft ≫ Exchange Server Version 2019 Update cumulative_update_5
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Microsoft ≫ Exchange Server Version 2019 Update cumulative_update_7
Microsoft ≫ Exchange Server Version 2019 Update cumulative_update_8

03.11.2021: CISA Known Exploited Vulnerabilities (KEV) Catalog

Microsoft Exchange Server Remote Code Execution Vulnerability

Schwachstelle

Microsoft Exchange Server contains an unspecified vulnerability that allows for remote code execution. This vulnerability is part of the ProxyLogon exploit chain.

Beschreibung

Apply updates per vendor instructions.

Erforderliche Maßnahmen
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 100% 1
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
NIST 7.5 10 6.4
AV:N/AC:L/Au:N/C:P/I:P/A:P
NIST 9.8 3.9 5.9
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Microsoft 9.1 3.9 5.2
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CWE-918 Server-Side Request Forgery (SSRF)

The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.

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Media Report
16.09.2026 18:41
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26.08.2026 20:03
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Media Report
26.06.2026 21:08
http://packetstormsecurity.com/files/161846/Microsoft-Exchange-2019-SSRF-Arbitrary-File-Write.html
Third Party Advisory
Exploit
VDB Entry
http://packetstormsecurity.com/files/161938/Microsoft-Exchange-ProxyLogon-Remote-Code-Execution.html
Third Party Advisory
Exploit
VDB Entry
http://packetstormsecurity.com/files/162610/Microsoft-Exchange-2019-Unauthenticated-Email-Download.html
Third Party Advisory
Exploit
VDB Entry
http://packetstormsecurity.com/files/162736/Microsoft-Exchange-ProxyLogon-Collector.html
Third Party Advisory
Exploit
VDB Entry
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26855
Patch
Vendor Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-26855
US Government Resource
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-26855
Patch
Vendor Advisory