Microsoft Exchange Server Remote Code Execution Vulnerability

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

Technical Severity

HIGH

8.8 / 10

Minimal Risk Critical

Vector Specification

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

Exploitation Likelihood

93.42 %

Predictive Probability

Percentile Rank

99.8 th

Documented as more likely to be exploited than 99.8% of known CVEs.

Detection Date

Nov 17, 2021

Remediation Due

Dec 01, 2021

CISA Catalog Active

Threat Analysis

An authenticated attacker could leverage improper validation in cmdlet arguments within Microsoft Exchange and perform remote code execution.

Apply updates per vendor instructions.

Vendor Identity

Microsoft

Affected Product

Exchange

Ransomware Status

Campaign Use Known

Weakness Classification

National Vulnerability Database

https://nvd.nist.gov/vuln/detail/CVE-2021-42321