Fixed Intel

CISA Known Exploited Vulnerability

This vulnerability is actively exploited in the wild and listed in the CISA Known Exploited Vulnerabilities catalog.

Remediation Deadline: May 3, 2022

CVE-2021-26857

High
EPSS 44.8%CISA KEVRansomware
Microsoft/Exchange Server

Description

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

EPSS — Exploit Probability

44.8%

Higher than 97.5% of all CVEs

Required Action

Reference CISA's ED 21-02 (https://www.cisa.gov/news-events/directives/ed-21-02-mitigate-microsoft-exchange-premises-product-vulnerabilities) for further guidance and requirements. Note: The due date for addressing this vulnerability aligns with the requirements outlined in ED 21-02. https://nvd.nist.gov/vuln/detail/CVE-2021-26857

Risk Assessment

HIGH
In CISA KEV
Ransomware

Details

Severity
High
EPSS
44.8%
CISA KEV
Yes
Ransomware
Known
Articles
0

Timeline

Published

Nov 3, 2021

Added to KEV

Nov 3, 2021

Remediation Due

May 3, 2022

Affected Product

Microsoft

Exchange Server

View all Microsoft CVEs