CVE-2021-34473

Microsoft Exchange Server Remote Code Execution Vulnerability

Severity Score

9.1

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

Yes

*KEV

Decision

*SSVC

Descriptions

Microsoft Exchange Server Remote Code Execution Vulnerability

Una vulnerabilidad de Ejecución de Código Remota de Microsoft Exchange Server. Este ID de CVE es diferente de CVE-2021-31196, CVE-2021-31206

This vulnerability allows remote attackers to execute arbitrary code on affected installations of Microsoft Exchange Server. Authentication is not required to exploit this vulnerability.
The specific flaw exists within the Autodiscover service. The issue results from the lack of proper validation of URI prior to accessing resources. An attacker can leverage this in conjunction with other vulnerabilities to execute arbitrary code in the context of SYSTEM.

Microsoft Exchange Server contains an unspecified vulnerability that allows for remote code execution.

*Credits: orangetw

CVSS Scores

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

None

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Changed

Confidentiality

High

Integrity

High

Availability

High

Attack Vector

Network

Attack Complexity

Low

Authentication

None

Confidentiality

Complete

Integrity

Complete

Availability

Complete

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2021-06-09 CVE Reserved
2021-07-14 CVE Published
2021-08-11 First Exploit
2021-11-03 Exploited in Wild
2021-11-17 KEV Due Date
2024-08-04 CVE Updated
2024-11-16 EPSS Updated

CWE

CWE-918: Server-Side Request Forgery (SSRF)

CAPEC

References (8)

URL	Tag	Source
https://www.zerodayinitiative.com/advisories/ZDI-21-821	Third Party Advisory

URL	Date	SRC
https://github.com/p2-98/CVE-2021-34473	2021-08-16
https://github.com/je6k/CVE-2021-34473-Exchange-ProxyShell	2021-11-23
https://github.com/RaouzRouik/CVE-2021-34473-scanner	2021-08-11
https://github.com/ipsBruno/CVE-2021-34473-NMAP-SCANNER	2022-11-16
https://github.com/jrgdiaz/ProxyShell-CVE-2021-34473.py	2022-01-17
http://packetstormsecurity.com/files/163895/Microsoft-Exchange-ProxyShell-Remote-Code-Execution.html	2024-08-04

URL	Date	SRC
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34473	2023-12-28

URL	Date	SRC

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Microsoft Search vendor "Microsoft"		Exchange Server Search vendor "Microsoft" for product "Exchange Server"				2013 Search vendor "Microsoft" for product "Exchange Server" and version "2013"		cumulative_update_23		Affected
Microsoft Search vendor "Microsoft"		Exchange Server Search vendor "Microsoft" for product "Exchange Server"				2016 Search vendor "Microsoft" for product "Exchange Server" and version "2016"		cumulative_update_19		Affected
Microsoft Search vendor "Microsoft"		Exchange Server Search vendor "Microsoft" for product "Exchange Server"				2016 Search vendor "Microsoft" for product "Exchange Server" and version "2016"		cumulative_update_20		Affected
Microsoft Search vendor "Microsoft"		Exchange Server Search vendor "Microsoft" for product "Exchange Server"				2019 Search vendor "Microsoft" for product "Exchange Server" and version "2019"		cumulative_update_8		Affected
Microsoft Search vendor "Microsoft"		Exchange Server Search vendor "Microsoft" for product "Exchange Server"				2019 Search vendor "Microsoft" for product "Exchange Server" and version "2019"		cumulative_update_9		Affected