Microsoft Exchange Server Remote Code Execution Vulnerability
CVE-2021-26858

7.8HIGH

What is CVE-2021-26858?

Microsoft Exchange Server Remote Code Execution Vulnerability

CISA has reported CVE-2021-26858

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 CVE-2021-26858 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 21 x64-based Systems 15.00.0

Microsoft Exchange Server 2013 Cumulative Update 22 x64-based Systems 15.00.0

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

References

EPSS Score

77% chance of being exploited in the next 30 days.

CVSS V3.1

Score:
7.8
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Local
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
Required
Scope:
Unchanged

Timeline

  • 💰

    Used in Ransomware

  • 👾

    Exploit known to exist

  • 🦅

    CISA Reported

  • Vulnerability published

  • Vulnerability Reserved

.