CVE-2021-42321highunder attackransomware

CVE-2021-42321: high-severity vulnerability in Microsoft Exchange Server 2016 Cumulative…

Microsoft Exchange Server Remote Code Execution Vulnerability

Published · Updated

Follow this CVE+ Monitor Microsoft Exchange Server

E-mail alert when it lands in KEV, gets a public PoC or its score goes up.

100Vexday Risk Score

Patch now. It under exploitation confirmed by CISA and has a working public exploit.

ssvc Actcvss 8.8epss 92%
from disclosure to weapon13 days
Published on NVDNov 10
1st PoC+13d
metasploit+29d
CISA KEV+7d
Action required by CISAfederal deadline: 2021-12-01

Apply updates per vendor instructions.

In short

A critical vulnerability in Microsoft Exchange Server allows attackers to execute arbitrary code remotely without authentication. This can give attackers complete control over email servers and the data they contain.

Technical detail

Unauthenticated remote code execution in Microsoft Exchange Server via deserialization of untrusted data in the Unified Messaging service. The vulnerability requires network access to the affected service and allows an attacker to execute arbitrary code with the privileges of the Exchange process.

Summary generated and translated by AI from the official description.

The full analysis of this CVE is available in Portuguese →

Microsoft Exchange Server Remote Code Execution Vulnerability
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
Affected products
Microsoft · Microsoft Exchange Server 2016 Cumulative Update 21Microsoft · Microsoft Exchange Server 2016 Cumulative Update 22Microsoft · Microsoft Exchange Server 2019 Cumulative Update 10Microsoft · Microsoft Exchange Server 2019 Cumulative Update 11
⚠ Public resources, to assess the exposure of systems you control or are authorized to test. Test only with authorization.
Related CVEs — Microsoft Exchange Server 2016 Cumulative…

In the same product, most dangerous first.

CVE-2022-41082HIGHMicrosoft Exchange Server Remote Code Execution VulnerabilityEPSS 100.0%KEVCVE-2022-41040HIGHMicrosoft Exchange Server Elevation of Privilege VulnerabilityEPSS 100.0%KEVCVE-2022-41080HIGHMicrosoft Exchange Server Elevation of Privilege VulnerabilityEPSS 77.3%KEVCVE-2021-31196HIGHMicrosoft Exchange Server Remote Code Execution VulnerabilityEPSS 54.1%KEVCVE-2021-41349MEDIUMMicrosoft Exchange Server Spoofing VulnerabilityEPSS 93.5%CVE-2022-23277HIGHMicrosoft Exchange Server Remote Code Execution VulnerabilityEPSS 41.1%