Microsoft Exchange Server Security Feature Bypass Vulnerability

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

Technical Severity

MEDIUM

6.6 / 10

Minimal Risk Critical

Vector Specification

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

Exploitation Likelihood

93.91 %

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

Nov 17, 2021

CISA Catalog Active

Threat Analysis

Microsoft Exchange Server contains an unspecified vulnerability that allows for security feature bypass.

Apply updates per vendor instructions.

Vendor Identity

Microsoft

Affected Product

Exchange Server

Ransomware Status

Campaign Use Known

Weakness Classification

National Vulnerability Database

https://nvd.nist.gov/vuln/detail/CVE-2021-31207