Microsoft Exchange Server Remote Code Execution Vulnerability

Critical Threat Advisory: This vulnerability is documented in active Ransomware campaigns. Immediate remediation required.

Technical Severity

CVSS v3.1 Metrics

CRITICAL

9.1 / 10

Minimal Risk Critical

Vector Specification

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N/E:F/RL:O/RC:C

Exploitation Likelihood

EPSS Prediction

94.31 %

Predictive Probability

Percentile Rank

99.9 th

Documented as more likely to be exploited than 99.9% of known CVEs.

Detection Date

Nov 03, 2021

Remediation Due

May 03, 2022

CISA Catalog Active

Threat Analysis

Microsoft Exchange Server contains an unspecified vulnerability that allows for remote code execution. This vulnerability is part of the ProxyLogon exploit chain.

Remediation Directive

Apply updates per vendor instructions.

Asset Context

Vendor Identity

Microsoft

Affected Product

Exchange Server

Ransomware Status

Campaign Use Known

Weakness Classification

CWE-918

External Intelligence

CISA

CISA Advisory

https://www.cisa.gov/news-events/directives/ed-21-02-mitigate-microsoft-exchange-premises-product-vulnerabilities)