Vulnerability-Lookup

BDU:2021-01123

Vulnerability from fstec - Published: 02.03.2021

Title

Уязвимость почтового сервера Microsoft Exchange Server, связанная с недостаточной проверкой поступающих запросов, позволяющая нарушителю осуществить SSRF-атаку

Description

Уязвимость почтового сервера Microsoft Exchange Server связана с недостаточной проверкой поступающих запросов. Эксплуатация уязвимости может позволить нарушителю, действующему удалённо, осуществить SSRF-атаку с помощью специально сформированных HTTPS-запросов (содержащих вредоносные файлы cookie X-AnonResource-Backend и искаженные файлы cookie X-BEResource)

Severity ?


                    
                      AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Vendor

Microsoft Corp

Software Name

Microsoft Exchange Server

Software Version

2016 Cumulative Update 8 (Microsoft Exchange Server), 2016 Cumulative Update 9 (Microsoft Exchange Server), 2013 Cumulative Update 21 (Microsoft Exchange Server), 2016 Cumulative Update 10 (Microsoft Exchange Server), 2016 Cumulative Update 11 (Microsoft Exchange Server), 2019 (Microsoft Exchange Server), 2013 Cumulative Update 22 (Microsoft Exchange Server), 2016 Cumulative Update 12 (Microsoft Exchange Server), 2019 Cumulative Update 1 (Microsoft Exchange Server), 2016 Cumulative Update 19 (Microsoft Exchange Server), 2013 Cumulative Update 23 (Microsoft Exchange Server), 2016 Cumulative Update 13 (Microsoft Exchange Server), 2019 Cumulative Update 2 (Microsoft Exchange Server), 2016 Cumulative Update 14 (Microsoft Exchange Server), 2019 Cumulative Update 3 (Microsoft Exchange Server), 2016 Cumulative Update 16 (Microsoft Exchange Server), 2016 Cumulative Update 17 (Microsoft Exchange Server), 2019 Cumulative Update 5 (Microsoft Exchange Server), 2019 Cumulative Update 6 (Microsoft Exchange Server), 2016 Cumulative Update 18 (Microsoft Exchange Server), 2019 Cumulative Update 7 (Microsoft Exchange Server), 2019 Cumulative Update 8 (Microsoft Exchange Server), 2016 Cumulative Update 15 (Microsoft Exchange Server), 2019 Cumulative Update 4 (Microsoft Exchange Server)

Possible Mitigations

Использование рекомендаций: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-26855

Reference

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-26855 https://nvd.nist.gov/vuln/detail/CVE-2021-26855 https://www.cybersecurity-help.cz/vdb/SB2021030301 https://msrc-blog.microsoft.com/2021/03/05/microsoft-exchange-server-vulnerabilities-mitigations-march-2021/

CWE

CWE-918

JSON

To clipboard

{
  "CVSS 2.0": "AV:N/AC:L/Au:N/C:C/I:C/A:C",
  "CVSS 3.0": "AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
  "CVSS 4.0": null,
  "remediation_\u0418\u0434\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0442\u043e\u0440": null,
  "remediation_\u041d\u0430\u0438\u043c\u0435\u043d\u043e\u0432\u0430\u043d\u0438\u0435": null,
  "\u0412\u0435\u043d\u0434\u043e\u0440 \u041f\u041e": "Microsoft Corp",
  "\u0412\u0435\u0440\u0441\u0438\u044f \u041f\u041e": "2016 Cumulative Update 8 (Microsoft Exchange Server), 2016 Cumulative Update 9 (Microsoft Exchange Server), 2013 Cumulative Update 21 (Microsoft Exchange Server), 2016 Cumulative Update 10 (Microsoft Exchange Server), 2016 Cumulative Update 11 (Microsoft Exchange Server), 2019 (Microsoft Exchange Server), 2013 Cumulative Update 22 (Microsoft Exchange Server), 2016 Cumulative Update 12 (Microsoft Exchange Server), 2019 Cumulative Update 1 (Microsoft Exchange Server), 2016 Cumulative Update 19 (Microsoft Exchange Server), 2013 Cumulative Update 23 (Microsoft Exchange Server), 2016 Cumulative Update 13 (Microsoft Exchange Server), 2019 Cumulative Update 2 (Microsoft Exchange Server), 2016 Cumulative Update 14 (Microsoft Exchange Server), 2019 Cumulative Update 3 (Microsoft Exchange Server), 2016 Cumulative Update 16 (Microsoft Exchange Server), 2016 Cumulative Update 17 (Microsoft Exchange Server), 2019 Cumulative Update 5 (Microsoft Exchange Server), 2019 Cumulative Update 6 (Microsoft Exchange Server), 2016 Cumulative Update 18 (Microsoft Exchange Server), 2019 Cumulative Update 7 (Microsoft Exchange Server), 2019 Cumulative Update 8 (Microsoft Exchange Server), 2016 Cumulative Update 15 (Microsoft Exchange Server), 2019 Cumulative Update 4 (Microsoft Exchange Server)",
  "\u0412\u043e\u0437\u043c\u043e\u0436\u043d\u044b\u0435 \u043c\u0435\u0440\u044b \u043f\u043e \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0438\u044e": "\u0418\u0441\u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u043d\u0438\u0435 \u0440\u0435\u043a\u043e\u043c\u0435\u043d\u0434\u0430\u0446\u0438\u0439:\nhttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-26855",
  "\u0414\u0430\u0442\u0430 \u0432\u044b\u044f\u0432\u043b\u0435\u043d\u0438\u044f": "02.03.2021",
  "\u0414\u0430\u0442\u0430 \u043f\u043e\u0441\u043b\u0435\u0434\u043d\u0435\u0433\u043e \u043e\u0431\u043d\u043e\u0432\u043b\u0435\u043d\u0438\u044f": "29.11.2021",
  "\u0414\u0430\u0442\u0430 \u043f\u0443\u0431\u043b\u0438\u043a\u0430\u0446\u0438\u0438": "03.03.2021",
  "\u0418\u0434\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0442\u043e\u0440": "BDU:2021-01123",
  "\u0418\u0434\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0442\u043e\u0440\u044b \u0434\u0440\u0443\u0433\u0438\u0445 \u0441\u0438\u0441\u0442\u0435\u043c \u043e\u043f\u0438\u0441\u0430\u043d\u0438\u0439 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "CVE-2021-26855",
  "\u0418\u043d\u0444\u043e\u0440\u043c\u0430\u0446\u0438\u044f \u043e\u0431 \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0438\u0438": "\u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0430",
  "\u041a\u043b\u0430\u0441\u0441 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u043a\u043e\u0434\u0430",
  "\u041d\u0430\u0437\u0432\u0430\u043d\u0438\u0435 \u041f\u041e": "Microsoft Exchange Server",
  "\u041d\u0430\u0438\u043c\u0435\u043d\u043e\u0432\u0430\u043d\u0438\u0435 \u041e\u0421 \u0438 \u0442\u0438\u043f \u0430\u043f\u043f\u0430\u0440\u0430\u0442\u043d\u043e\u0439 \u043f\u043b\u0430\u0442\u0444\u043e\u0440\u043c\u044b": null,
  "\u041d\u0430\u0438\u043c\u0435\u043d\u043e\u0432\u0430\u043d\u0438\u0435 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u043f\u043e\u0447\u0442\u043e\u0432\u043e\u0433\u043e \u0441\u0435\u0440\u0432\u0435\u0440\u0430 Microsoft Exchange Server, \u0441\u0432\u044f\u0437\u0430\u043d\u043d\u0430\u044f \u0441 \u043d\u0435\u0434\u043e\u0441\u0442\u0430\u0442\u043e\u0447\u043d\u043e\u0439 \u043f\u0440\u043e\u0432\u0435\u0440\u043a\u043e\u0439 \u043f\u043e\u0441\u0442\u0443\u043f\u0430\u044e\u0449\u0438\u0445 \u0437\u0430\u043f\u0440\u043e\u0441\u043e\u0432, \u043f\u043e\u0437\u0432\u043e\u043b\u044f\u044e\u0449\u0430\u044f \u043d\u0430\u0440\u0443\u0448\u0438\u0442\u0435\u043b\u044e \u043e\u0441\u0443\u0449\u0435\u0441\u0442\u0432\u0438\u0442\u044c SSRF-\u0430\u0442\u0430\u043a\u0443",
  "\u041d\u0430\u043b\u0438\u0447\u0438\u0435 \u044d\u043a\u0441\u043f\u043b\u043e\u0439\u0442\u0430": "\u0421\u0443\u0449\u0435\u0441\u0442\u0432\u0443\u0435\u0442 \u0432 \u043e\u0442\u043a\u0440\u044b\u0442\u043e\u043c \u0434\u043e\u0441\u0442\u0443\u043f\u0435",
  "\u041e\u043f\u0438\u0441\u0430\u043d\u0438\u0435 \u043e\u0448\u0438\u0431\u043a\u0438 CWE": "\u0421\u0435\u0440\u0432\u0435\u0440\u043d\u0430\u044f \u0444\u0430\u043b\u044c\u0441\u0438\u0444\u0438\u043a\u0430\u0446\u0438\u044f \u0437\u0430\u043f\u0440\u043e\u0441\u043e\u0432 (CWE-918)",
  "\u041e\u043f\u0438\u0441\u0430\u043d\u0438\u0435 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u043f\u043e\u0447\u0442\u043e\u0432\u043e\u0433\u043e \u0441\u0435\u0440\u0432\u0435\u0440\u0430 Microsoft Exchange Server \u0441\u0432\u044f\u0437\u0430\u043d\u0430 \u0441 \u043d\u0435\u0434\u043e\u0441\u0442\u0430\u0442\u043e\u0447\u043d\u043e\u0439 \u043f\u0440\u043e\u0432\u0435\u0440\u043a\u043e\u0439 \u043f\u043e\u0441\u0442\u0443\u043f\u0430\u044e\u0449\u0438\u0445 \u0437\u0430\u043f\u0440\u043e\u0441\u043e\u0432. \u042d\u043a\u0441\u043f\u043b\u0443\u0430\u0442\u0430\u0446\u0438\u044f \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438 \u043c\u043e\u0436\u0435\u0442 \u043f\u043e\u0437\u0432\u043e\u043b\u0438\u0442\u044c \u043d\u0430\u0440\u0443\u0448\u0438\u0442\u0435\u043b\u044e, \u0434\u0435\u0439\u0441\u0442\u0432\u0443\u044e\u0449\u0435\u043c\u0443 \u0443\u0434\u0430\u043b\u0451\u043d\u043d\u043e, \u043e\u0441\u0443\u0449\u0435\u0441\u0442\u0432\u0438\u0442\u044c SSRF-\u0430\u0442\u0430\u043a\u0443 \u0441 \u043f\u043e\u043c\u043e\u0449\u044c\u044e \u0441\u043f\u0435\u0446\u0438\u0430\u043b\u044c\u043d\u043e \u0441\u0444\u043e\u0440\u043c\u0438\u0440\u043e\u0432\u0430\u043d\u043d\u044b\u0445 HTTPS-\u0437\u0430\u043f\u0440\u043e\u0441\u043e\u0432 (\u0441\u043e\u0434\u0435\u0440\u0436\u0430\u0449\u0438\u0445 \u0432\u0440\u0435\u0434\u043e\u043d\u043e\u0441\u043d\u044b\u0435 \u0444\u0430\u0439\u043b\u044b cookie X-AnonResource-Backend \u0438 \u0438\u0441\u043a\u0430\u0436\u0435\u043d\u043d\u044b\u0435 \u0444\u0430\u0439\u043b\u044b cookie X-BEResource)",
  "\u041f\u043e\u0441\u043b\u0435\u0434\u0441\u0442\u0432\u0438\u044f \u044d\u043a\u0441\u043f\u043b\u0443\u0430\u0442\u0430\u0446\u0438\u0438 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": null,
  "\u041f\u0440\u043e\u0447\u0430\u044f \u0438\u043d\u0444\u043e\u0440\u043c\u0430\u0446\u0438\u044f": null,
  "\u0421\u0432\u044f\u0437\u044c \u0441 \u0438\u043d\u0446\u0438\u0434\u0435\u043d\u0442\u0430\u043c\u0438 \u0418\u0411": "\u0414\u0430",
  "\u0421\u043e\u0441\u0442\u043e\u044f\u043d\u0438\u0435 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u041e\u043f\u0443\u0431\u043b\u0438\u043a\u043e\u0432\u0430\u043d\u0430",
  "\u0421\u043f\u043e\u0441\u043e\u0431 \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0438\u044f": "\u041e\u0431\u043d\u043e\u0432\u043b\u0435\u043d\u0438\u0435 \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u043d\u043e\u0433\u043e \u043e\u0431\u0435\u0441\u043f\u0435\u0447\u0435\u043d\u0438\u044f",
  "\u0421\u043f\u043e\u0441\u043e\u0431 \u044d\u043a\u0441\u043f\u043b\u0443\u0430\u0442\u0430\u0446\u0438\u0438": "\u041f\u043e\u0434\u043c\u0435\u043d\u0430 \u043f\u0440\u0438 \u0432\u0437\u0430\u0438\u043c\u043e\u0434\u0435\u0439\u0441\u0442\u0432\u0438\u0438",
  "\u0421\u0441\u044b\u043b\u043a\u0438 \u043d\u0430 \u0438\u0441\u0442\u043e\u0447\u043d\u0438\u043a\u0438": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-26855\nhttps://nvd.nist.gov/vuln/detail/CVE-2021-26855\nhttps://www.cybersecurity-help.cz/vdb/SB2021030301\nhttps://msrc-blog.microsoft.com/2021/03/05/microsoft-exchange-server-vulnerabilities-mitigations-march-2021/",
  "\u0421\u0442\u0430\u0442\u0443\u0441 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u041f\u043e\u0434\u0442\u0432\u0435\u0440\u0436\u0434\u0435\u043d\u0430 \u043f\u0440\u043e\u0438\u0437\u0432\u043e\u0434\u0438\u0442\u0435\u043b\u0435\u043c",
  "\u0422\u0438\u043f \u041f\u041e": "\u041f\u0440\u0438\u043a\u043b\u0430\u0434\u043d\u043e\u0435 \u041f\u041e \u0438\u043d\u0444\u043e\u0440\u043c\u0430\u0446\u0438\u043e\u043d\u043d\u044b\u0445 \u0441\u0438\u0441\u0442\u0435\u043c",
  "\u0422\u0438\u043f \u043e\u0448\u0438\u0431\u043a\u0438 CWE": "CWE-918",
  "\u0423\u0440\u043e\u0432\u0435\u043d\u044c \u043e\u043f\u0430\u0441\u043d\u043e\u0441\u0442\u0438 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u041a\u0440\u0438\u0442\u0438\u0447\u0435\u0441\u043a\u0438\u0439 \u0443\u0440\u043e\u0432\u0435\u043d\u044c \u043e\u043f\u0430\u0441\u043d\u043e\u0441\u0442\u0438 (\u0431\u0430\u0437\u043e\u0432\u0430\u044f \u043e\u0446\u0435\u043d\u043a\u0430 CVSS 2.0 \u0441\u043e\u0441\u0442\u0430\u0432\u043b\u044f\u0435\u0442 10)\n\u041a\u0440\u0438\u0442\u0438\u0447\u0435\u0441\u043a\u0438\u0439 \u0443\u0440\u043e\u0432\u0435\u043d\u044c \u043e\u043f\u0430\u0441\u043d\u043e\u0441\u0442\u0438 (\u0431\u0430\u0437\u043e\u0432\u0430\u044f \u043e\u0446\u0435\u043d\u043a\u0430 CVSS 3.0 \u0441\u043e\u0441\u0442\u0430\u0432\u043b\u044f\u0435\u0442 9,8)"
}

CVE-2021-26855 (GCVE-0-2021-26855)

Vulnerability from cvelistv5 – Published: 2021-03-02 23:55 – Updated: 2025-10-21 23:25

Title

Microsoft Exchange Server Remote Code Execution Vulnerability

Summary

Microsoft Exchange Server Remote Code Execution Vulnerability

Severity ?

9.1 (Critical)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N/E:F/RL:O/RC:C

CWE

Remote Code Execution

Assigner

microsoft

References

URL

Tags

	https://portal.msrc.microsoft.com/en-US/security-…	x_refsource_MISC
	http://packetstormsecurity.com/files/161846/Micro…	x_refsource_MISC
	http://packetstormsecurity.com/files/161938/Micro…	x_refsource_MISC
	http://packetstormsecurity.com/files/162610/Micro…	x_refsource_MISC
	http://packetstormsecurity.com/files/162736/Micro…	x_refsource_MISC

Impacted products

Vendor

Product

Version

Microsoft

Microsoft Exchange Server 2016 Cumulative Update 19

Affected: 15.01.0 , < publication (custom)
cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_19:*:*:*:*:*:*

Microsoft	Microsoft Exchange Server 2019 Cumulative Update 8	Affected: 15.02.0 , < publication (custom) cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_8::::::
Microsoft	Microsoft Exchange Server 2019	Affected: 15.02.0 , < publication (custom) cpe:2.3:a:microsoft:exchange_server:2019:::::::*
Microsoft	Microsoft Exchange Server 2013 Cumulative Update 22	Affected: 15.00.0 , < publication (custom) cpe:2.3:a:microsoft:exchange_server:2013:cumulative_update_22::::::
Microsoft	Microsoft Exchange Server 2019 Cumulative Update 2	Affected: 15.02.0 , < publication (custom) cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_2::::::
Microsoft	Microsoft Exchange Server 2016 Cumulative Update 13	Affected: 15.01.0 , < publication (custom) cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_13::::::
Microsoft	Microsoft Exchange Server 2013 Cumulative Update 23	Affected: 15.00.0 , < publication (custom) cpe:2.3:a:microsoft:exchange_server:2013:cumulative_update_23::::::
Microsoft	Microsoft Exchange Server 2019 Cumulative Update 3	Affected: 15.02.0 , < publication (custom) cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_3::::::
Microsoft	Microsoft Exchange Server 2016 Cumulative Update 14	Affected: 15.01.0 , < publication (custom) cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_14::::::
Microsoft	Microsoft Exchange Server 2019 Cumulative Update 4	Affected: 15.02.0 , < publication (custom) cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_4::::::
Microsoft	Microsoft Exchange Server 2016 Cumulative Update 15	Affected: 15.01.0 , < publication (custom) cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_15::::::
Microsoft	Microsoft Exchange Server 2019 Cumulative Update 5	Affected: 15.02.0 , < publication (custom) cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_5::::::
Microsoft	Microsoft Exchange Server 2019 Cumulative Update 6	Affected: 15.02.0 , < publication (custom) cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_6::::::
Microsoft	Microsoft Exchange Server 2016 Cumulative Update 16	Affected: 15.01.0 , < publication (custom) cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_16::::::
Microsoft	Microsoft Exchange Server 2016 Cumulative Update 17	Affected: 15.01.0 , < publication (custom) cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_17::::::
Microsoft	Microsoft Exchange Server 2019 Cumulative Update 7	Affected: 15.02.0 , < publication (custom) cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_7::::::
Microsoft	Microsoft Exchange Server 2016 Cumulative Update 18	Affected: 15.01.0 , < publication (custom) cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_18::::::
Microsoft	Microsoft Exchange Server 2013 Cumulative Update 21	Affected: 15.00.0 , < publication (custom) cpe:2.3:a:microsoft:exchange_server:2013:cumulative_update_21::::::
Microsoft	Microsoft Exchange Server 2016 Cumulative Update 12	Affected: 15.01.0 , < publication (custom) cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_12::::::
Microsoft	Microsoft Exchange Server 2016 Cumulative Update 8	Affected: 15.01.0 , < publication (custom) cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_8::::::
Microsoft	Microsoft Exchange Server 2019 Cumulative Update 1	Affected: 15.02.0 , < publication (custom) cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_1::::::
Microsoft	Microsoft Exchange Server 2016 Cumulative Update 9	Affected: 15.01.0 , < publication (custom) cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_9::::::
Microsoft	Microsoft Exchange Server 2016 Cumulative Update 10	Affected: 15.01.0 , < publication (custom) cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_10::::::
Microsoft	Microsoft Exchange Server 2016 Cumulative Update 11	Affected: 15.01.0 , < publication (custom) cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_11::::::

Date Public ?

2021-03-02 08:00

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-03T20:33:40.999Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26855"
          },
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "http://packetstormsecurity.com/files/161846/Microsoft-Exchange-2019-SSRF-Arbitrary-File-Write.html"
          },
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "http://packetstormsecurity.com/files/161938/Microsoft-Exchange-ProxyLogon-Remote-Code-Execution.html"
          },
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "http://packetstormsecurity.com/files/162610/Microsoft-Exchange-2019-Unauthenticated-Email-Download.html"
          },
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "http://packetstormsecurity.com/files/162736/Microsoft-Exchange-ProxyLogon-Collector.html"
          }
        ],
        "title": "CVE Program Container"
      },
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2021-26855",
                "options": [
                  {
                    "Exploitation": "active"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2024-01-02T18:10:15.970217Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          },
          {
            "other": {
              "content": {
                "dateAdded": "2021-11-03",
                "reference": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-26855"
              },
              "type": "kev"
            }
          }
        ],
        "problemTypes": [
          {
            "descriptions": [
              {
                "cweId": "CWE-918",
                "description": "CWE-918 Server-Side Request Forgery (SSRF)",
                "lang": "en",
                "type": "CWE"
              }
            ]
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2025-10-21T23:25:53.200Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "government-resource"
            ],
            "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-26855"
          }
        ],
        "timeline": [
          {
            "lang": "en",
            "time": "2021-11-03T00:00:00.000Z",
            "value": "CVE-2021-26855 added to CISA KEV"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "cpes": [
            "cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_19:*:*:*:*:*:*"
          ],
          "platforms": [
            "x64-based Systems"
          ],
          "product": "Microsoft Exchange Server 2016 Cumulative Update 19",
          "vendor": "Microsoft",
          "versions": [
            {
              "lessThan": "publication",
              "status": "affected",
              "version": "15.01.0",
              "versionType": "custom"
            }
          ]
        },
        {
          "cpes": [
            "cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_8:*:*:*:*:*:*"
          ],
          "platforms": [
            "x64-based Systems"
          ],
          "product": "Microsoft Exchange Server 2019 Cumulative Update 8",
          "vendor": "Microsoft",
          "versions": [
            {
              "lessThan": "publication",
              "status": "affected",
              "version": "15.02.0",
              "versionType": "custom"
            }
          ]
        },
        {
          "cpes": [
            "cpe:2.3:a:microsoft:exchange_server:2019:*:*:*:*:*:*:*"
          ],
          "platforms": [
            "x64-based Systems"
          ],
          "product": "Microsoft Exchange Server 2019",
          "vendor": "Microsoft",
          "versions": [
            {
              "lessThan": "publication",
              "status": "affected",
              "version": "15.02.0",
              "versionType": "custom"
            }
          ]
        },
        {
          "cpes": [
            "cpe:2.3:a:microsoft:exchange_server:2013:cumulative_update_22:*:*:*:*:*:*"
          ],
          "platforms": [
            "x64-based Systems"
          ],
          "product": "Microsoft Exchange Server 2013 Cumulative Update 22",
          "vendor": "Microsoft",
          "versions": [
            {
              "lessThan": "publication",
              "status": "affected",
              "version": "15.00.0",
              "versionType": "custom"
            }
          ]
        },
        {
          "cpes": [
            "cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_2:*:*:*:*:*:*"
          ],
          "platforms": [
            "x64-based Systems"
          ],
          "product": "Microsoft Exchange Server 2019 Cumulative Update 2",
          "vendor": "Microsoft",
          "versions": [
            {
              "lessThan": "publication",
              "status": "affected",
              "version": "15.02.0",
              "versionType": "custom"
            }
          ]
        },
        {
          "cpes": [
            "cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_13:*:*:*:*:*:*"
          ],
          "platforms": [
            "x64-based Systems"
          ],
          "product": "Microsoft Exchange Server 2016 Cumulative Update 13",
          "vendor": "Microsoft",
          "versions": [
            {
              "lessThan": "publication",
              "status": "affected",
              "version": "15.01.0",
              "versionType": "custom"
            }
          ]
        },
        {
          "cpes": [
            "cpe:2.3:a:microsoft:exchange_server:2013:cumulative_update_23:*:*:*:*:*:*"
          ],
          "platforms": [
            "x64-based Systems"
          ],
          "product": "Microsoft Exchange Server 2013 Cumulative Update 23",
          "vendor": "Microsoft",
          "versions": [
            {
              "lessThan": "publication",
              "status": "affected",
              "version": "15.00.0",
              "versionType": "custom"
            }
          ]
        },
        {
          "cpes": [
            "cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_3:*:*:*:*:*:*"
          ],
          "platforms": [
            "x64-based Systems"
          ],
          "product": "Microsoft Exchange Server 2019 Cumulative Update 3",
          "vendor": "Microsoft",
          "versions": [
            {
              "lessThan": "publication",
              "status": "affected",
              "version": "15.02.0",
              "versionType": "custom"
            }
          ]
        },
        {
          "cpes": [
            "cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_14:*:*:*:*:*:*"
          ],
          "platforms": [
            "x64-based Systems"
          ],
          "product": "Microsoft Exchange Server 2016 Cumulative Update 14",
          "vendor": "Microsoft",
          "versions": [
            {
              "lessThan": "publication",
              "status": "affected",
              "version": "15.01.0",
              "versionType": "custom"
            }
          ]
        },
        {
          "cpes": [
            "cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_4:*:*:*:*:*:*"
          ],
          "platforms": [
            "x64-based Systems"
          ],
          "product": "Microsoft Exchange Server 2019 Cumulative Update 4",
          "vendor": "Microsoft",
          "versions": [
            {
              "lessThan": "publication",
              "status": "affected",
              "version": "15.02.0",
              "versionType": "custom"
            }
          ]
        },
        {
          "cpes": [
            "cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_15:*:*:*:*:*:*"
          ],
          "platforms": [
            "x64-based Systems"
          ],
          "product": "Microsoft Exchange Server 2016 Cumulative Update 15",
          "vendor": "Microsoft",
          "versions": [
            {
              "lessThan": "publication",
              "status": "affected",
              "version": "15.01.0",
              "versionType": "custom"
            }
          ]
        },
        {
          "cpes": [
            "cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_5:*:*:*:*:*:*"
          ],
          "platforms": [
            "x64-based Systems"
          ],
          "product": "Microsoft Exchange Server 2019 Cumulative Update 5",
          "vendor": "Microsoft",
          "versions": [
            {
              "lessThan": "publication",
              "status": "affected",
              "version": "15.02.0",
              "versionType": "custom"
            }
          ]
        },
        {
          "cpes": [
            "cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_6:*:*:*:*:*:*"
          ],
          "platforms": [
            "x64-based Systems"
          ],
          "product": "Microsoft Exchange Server 2019 Cumulative Update 6",
          "vendor": "Microsoft",
          "versions": [
            {
              "lessThan": "publication",
              "status": "affected",
              "version": "15.02.0",
              "versionType": "custom"
            }
          ]
        },
        {
          "cpes": [
            "cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_16:*:*:*:*:*:*"
          ],
          "platforms": [
            "x64-based Systems"
          ],
          "product": "Microsoft Exchange Server 2016 Cumulative Update 16",
          "vendor": "Microsoft",
          "versions": [
            {
              "lessThan": "publication",
              "status": "affected",
              "version": "15.01.0",
              "versionType": "custom"
            }
          ]
        },
        {
          "cpes": [
            "cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_17:*:*:*:*:*:*"
          ],
          "platforms": [
            "x64-based Systems"
          ],
          "product": "Microsoft Exchange Server 2016 Cumulative Update 17",
          "vendor": "Microsoft",
          "versions": [
            {
              "lessThan": "publication",
              "status": "affected",
              "version": "15.01.0",
              "versionType": "custom"
            }
          ]
        },
        {
          "cpes": [
            "cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_7:*:*:*:*:*:*"
          ],
          "platforms": [
            "x64-based Systems"
          ],
          "product": "Microsoft Exchange Server 2019 Cumulative Update 7",
          "vendor": "Microsoft",
          "versions": [
            {
              "lessThan": "publication",
              "status": "affected",
              "version": "15.02.0",
              "versionType": "custom"
            }
          ]
        },
        {
          "cpes": [
            "cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_18:*:*:*:*:*:*"
          ],
          "platforms": [
            "x64-based Systems"
          ],
          "product": "Microsoft Exchange Server 2016 Cumulative Update 18",
          "vendor": "Microsoft",
          "versions": [
            {
              "lessThan": "publication",
              "status": "affected",
              "version": "15.01.0",
              "versionType": "custom"
            }
          ]
        },
        {
          "cpes": [
            "cpe:2.3:a:microsoft:exchange_server:2013:cumulative_update_21:*:*:*:*:*:*"
          ],
          "platforms": [
            "x64-based Systems"
          ],
          "product": "Microsoft Exchange Server 2013 Cumulative Update 21",
          "vendor": "Microsoft",
          "versions": [
            {
              "lessThan": "publication",
              "status": "affected",
              "version": "15.00.0",
              "versionType": "custom"
            }
          ]
        },
        {
          "cpes": [
            "cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_12:*:*:*:*:*:*"
          ],
          "platforms": [
            "x64-based Systems"
          ],
          "product": "Microsoft Exchange Server 2016 Cumulative Update 12",
          "vendor": "Microsoft",
          "versions": [
            {
              "lessThan": "publication",
              "status": "affected",
              "version": "15.01.0",
              "versionType": "custom"
            }
          ]
        },
        {
          "cpes": [
            "cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_8:*:*:*:*:*:*"
          ],
          "platforms": [
            "x64-based Systems"
          ],
          "product": "Microsoft Exchange Server 2016 Cumulative Update 8",
          "vendor": "Microsoft",
          "versions": [
            {
              "lessThan": "publication",
              "status": "affected",
              "version": "15.01.0",
              "versionType": "custom"
            }
          ]
        },
        {
          "cpes": [
            "cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_1:*:*:*:*:*:*"
          ],
          "platforms": [
            "x64-based Systems"
          ],
          "product": "Microsoft Exchange Server 2019 Cumulative Update 1",
          "vendor": "Microsoft",
          "versions": [
            {
              "lessThan": "publication",
              "status": "affected",
              "version": "15.02.0",
              "versionType": "custom"
            }
          ]
        },
        {
          "cpes": [
            "cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_9:*:*:*:*:*:*"
          ],
          "platforms": [
            "x64-based Systems"
          ],
          "product": "Microsoft Exchange Server 2016 Cumulative Update 9",
          "vendor": "Microsoft",
          "versions": [
            {
              "lessThan": "publication",
              "status": "affected",
              "version": "15.01.0",
              "versionType": "custom"
            }
          ]
        },
        {
          "cpes": [
            "cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_10:*:*:*:*:*:*"
          ],
          "platforms": [
            "x64-based Systems"
          ],
          "product": "Microsoft Exchange Server 2016 Cumulative Update 10",
          "vendor": "Microsoft",
          "versions": [
            {
              "lessThan": "publication",
              "status": "affected",
              "version": "15.01.0",
              "versionType": "custom"
            }
          ]
        },
        {
          "cpes": [
            "cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_11:*:*:*:*:*:*"
          ],
          "platforms": [
            "x64-based Systems"
          ],
          "product": "Microsoft Exchange Server 2016 Cumulative Update 11",
          "vendor": "Microsoft",
          "versions": [
            {
              "lessThan": "publication",
              "status": "affected",
              "version": "15.01.0",
              "versionType": "custom"
            }
          ]
        }
      ],
      "datePublic": "2021-03-02T08:00:00.000Z",
      "descriptions": [
        {
          "lang": "en-US",
          "value": "Microsoft Exchange Server Remote Code Execution Vulnerability"
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 9.1,
            "baseSeverity": "CRITICAL",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N/E:F/RL:O/RC:C",
            "version": "3.1"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en-US",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "description": "Remote Code Execution",
              "lang": "en-US",
              "type": "Impact"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2023-12-29T20:08:56.682Z",
        "orgId": "f38d906d-7342-40ea-92c1-6c4a2c6478c8",
        "shortName": "microsoft"
      },
      "references": [
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26855"
        },
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "http://packetstormsecurity.com/files/161846/Microsoft-Exchange-2019-SSRF-Arbitrary-File-Write.html"
        },
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "http://packetstormsecurity.com/files/161938/Microsoft-Exchange-ProxyLogon-Remote-Code-Execution.html"
        },
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "http://packetstormsecurity.com/files/162610/Microsoft-Exchange-2019-Unauthenticated-Email-Download.html"
        },
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "http://packetstormsecurity.com/files/162736/Microsoft-Exchange-ProxyLogon-Collector.html"
        }
      ],
      "title": "Microsoft Exchange Server Remote Code Execution Vulnerability"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "f38d906d-7342-40ea-92c1-6c4a2c6478c8",
    "assignerShortName": "microsoft",
    "cveId": "CVE-2021-26855",
    "datePublished": "2021-03-02T23:55:26.000Z",
    "dateReserved": "2021-02-08T00:00:00.000Z",
    "dateUpdated": "2025-10-21T23:25:53.200Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1"
}

Sightings

Author	Source	Type	Date

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

BDU:2021-01123

CVE-2021-26855 (GCVE-0-2021-26855)

Tags

Sightings

Nomenclature