// For flags

CVE-2021-31209

Microsoft Exchange Server Spoofing Vulnerability

Severity Score

6.5
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

Microsoft Exchange Server Spoofing Vulnerability

Una vulnerabilidad de SuplantaciĆ³n de Identidad de Microsoft Exchange Server

This vulnerability allows network-adjacent attackers to tamper with update data on affected installations of Microsoft Exchange Server. User interaction is required to exploit this vulnerability.
The specific flaw exists within the handling of Exchange Server Help updates. The issue results from a missing integrity check on update downloads. An attacker can leverage this in conjunction with other vulnerabilities to execute arbitrary code in the context of SYSTEM.

*Credits: Steven Seeley (mr_me) of Source Incite
CVSS Scores
Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
Low
Availability
None
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None
Attack Vector
Adjacent
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
None
Attack Vector
Network
Attack Complexity
Medium
Authentication
None
Confidentiality
Partial
Integrity
Partial
Availability
None
* 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
  • 2024-08-03 CVE Updated
  • 2024-10-31 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
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