// For flags

CVE-2021-31207

Microsoft Exchange Server Security Feature Bypass Vulnerability

Severity Score

6.6
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

1
*Multiple Sources

Exploited in Wild

Yes
*KEV

Decision

-
*SSVC
Descriptions

Microsoft Exchange Server Security Feature Bypass Vulnerability

Una vulnerabilidad de Omisión de la Característica de Seguridad de Microsoft Exchange Server

This vulnerability allows remote attackers to execute arbitrary code on affected installations of Microsoft Exchange Server. Although authentication is required to exploit this vulnerability, the existing authentication mechanism can be bypassed.
The specific flaw exists within the handling of mailbox export. The issue results from the lack of proper validation of user-supplied data, which can allow the upload of arbitrary files. An attacker can leverage this vulnerability to execute arbitrary code in the context of SYSTEM.

Microsoft Exchange Server contains an unspecified vulnerability that allows for security feature bypass.

*Credits: Orange Tsai(@orange_8361) from DEVCORE Research Team
CVSS Scores
Attack Vector
Network
Attack Complexity
High
Privileges Required
High
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Attack Vector
Network
Attack Complexity
Low
Privileges Required
High
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Attack Vector
Network
Attack Complexity
Low
Authentication
Single
Confidentiality
Partial
Integrity
Partial
Availability
Partial
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2021-04-14 CVE Reserved
  • 2021-05-11 CVE Published
  • 2021-11-03 Exploited in Wild
  • 2021-11-17 KEV Due Date
  • 2024-08-03 CVE Updated
  • 2024-08-03 First Exploit
  • 2024-10-14 EPSS Updated
CWE
  • CWE-434: Unrestricted Upload of File with Dangerous Type
CAPEC
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