Microsoft Exchange Server Security Feature Bypass Vulnerability
CVE-2021-31207

6.6MEDIUM

Key Information:

Vendor
Microsoft
Status
Microsoft Exchange Server 2013 Cumulative Update 23
Microsoft Exchange Server 2019 Cumulative Update 9
Microsoft Exchange Server 2016 Cumulative Update 20
Microsoft Exchange Server 2016 Cumulative Update 19
Vendor
CVE Published:
11 May 2021

Badges

💰 Ransomware👾 Exploit Exists🟣 EPSS 91%🦅 CISA Reported

Summary

Microsoft Exchange Server Security Feature Bypass Vulnerability

CISA Reported

CISA provides regional cyber and physical services to support security and resilience across the United States. CISA monitor the most dangerious vulnerabilities and have identifed as being exploited and is known by the CISA as enabling ransomware campaigns.

The CISA's recommendation is: Apply updates per vendor instructions.

Affected Version(s)

Microsoft Exchange Server 2013 Cumulative Update 23 x64-based Systems 15.00.0 < 15.00.1497.018

Microsoft Exchange Server 2016 Cumulative Update 19 Unknown 15.01.0.0 < 15.01.2176.014

Microsoft Exchange Server 2016 Cumulative Update 20 Unknown 15.01.0.0 < 15.01.2242.010

References

https://portal.msrc.microsoft.com/en-US/security-guidance...
x_refsource_MISC
https://www.zerodayinitiative.com/advisories/ZDI-21-819/
x_refsource_MISC
http://packetstormsecurity.com/files/163895/Microsoft-Exc...
x_refsource_MISC

EPSS Score

91% chance of being exploited in the next 30 days.

CVSS V3.1

Score:
6.6
Severity:
MEDIUM
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
High
Privileges Required:
High
User Interaction:
None
Scope:
Unchanged

Timeline

  • 💰

    Used in Ransomware

  • 👾

    Exploit known to exist

  • 🦅

    CISA Reported

  • Vulnerability published

  • Vulnerability Reserved

Collectors

NVD DatabaseMitre DatabaseCISA Database
.