Is CVE-2021-27065 actively exploited?

Yes. CVE-2021-27065 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, which means exploitation in the wild has been confirmed.

Can CVE-2021-27065 be exploited remotely?

The attack vector of CVE-2021-27065 has not been classified yet.

What is the CVSS score of CVE-2021-27065?

CVE-2021-27065 has not received a CVSS score yet.

HOME VULNERABILITIESCVE-2021-27065

HIGHCISA KEVIN THE WILD

CVE-2021-27065

Published: November 3, 2021

EPSS:94.28%probability of exploitation in 30 daysPercentile:99.9th

Official Description

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

NVD Source

CISA KEV Advisory

Microsoft Exchange Server Remote Code Execution Vulnerability

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

Added to KEV: 2021-11-03Federal patch deadline: 2022-05-03⚠ USED IN RANSOMWARE CAMPAIGNS

Required Action (CISA)

Apply updates per vendor instructions.

Risk Analysis

This unspecified vulnerability in Microsoft Exchange Server allows for remote code execution and is a component of the ProxyLogon exploit chain. The high EPSS score of 0.94282 and its inclusion in the KEV catalog underscore the critical urgency and high likelihood of exploitation.

This vulnerability is actively exploited in the wild and is confirmed by CISA to be part of known exploitation campaigns, indicating a severe and immediate threat. This vulnerability is remotely exploitable.

Recommended Action

Apply all available security updates for Microsoft Exchange Server to mitigate this remote code execution vulnerability. Regularly review and harden Exchange Server configurations.

Generated by the CTIWATCH analysis pipeline from this CVE's metadata (CVSS, EPSS, KEV status, exploit intelligence). Verify against vendor advisories before acting.

Technical Analysis

CVE-2021-27065 requires local access, meaning attackers must already have a foothold on the target system.

Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

CISA has added CVE-2021-27065 to the Known Exploited Vulnerabilities (KEV) catalog, confirming active exploitation in the wild. U.S. federal agencies are required to patch this within the mandated timeframe, and all organizations should treat remediation as urgent.