Live › vulnerability › CVE-2021-34473
Go to dashboardMicrosoft Exchange Server has a remote code execution flaw (ProxyShell family, CVE-2021-34473) that is actively exploited, with ransomware use noted in the sources. An unauthenticated attacker on the internet can run code on the mail server.
Summary written from the sources below. Check the originals before acting.
First seen by InfraStack 2026-10-23 19:11 UTC, 3h before NVD. All times on this page are UTC.
Apply updates per vendor instructions.
| Product | Ecosystem | Affected | Fixed in |
|---|---|---|---|
| Microsoft Exchange Server | vendor | – | – |
Unknown from the sources. In the analyst’s queue.
Apply the Microsoft updates for Exchange Server per vendor instructions (CISA required action); exact patch build is unknown from the sources.
Each row is the first time that source carried this signal. The analyst’s rows are its own findings.
Microsoft Exchange Server contains an unspecified vulnerability that allows for remote code execution.
CISA required action: Apply updates per vendor instructions.
This page as .md · .json · in your agent: get_signal("CVE-2021-34473")
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