Is CVE-2021-27065 exploited in the wild?

Yes. CVE-2021-27065 is known to be exploited in the wild, first recorded on 3 November 2021. Treat it as urgent.

How severe is CVE-2021-27065?

Critical severity, with a CVSS score of 7.8, published 3 November 2021.

Which products and versions are affected?

Microsoft Exchange Server 2013 Cumulative Update 21, 22, 23, Service Pack 1; Microsoft Exchange Server 2016 Cumulative Update 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19; Microsoft Exchange Server 2019 Cumulative Update 1, 2, 4, 5, 6, 7, 8.

Is there a fix for CVE-2021-27065?

No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

How is CVE-2021-27065 attacked?

It is attacked with local access, in a network appliance.

Am I affected by CVE-2021-27065?

Check whether you run Microsoft Exchange Server. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2021-27065: Microsoft Exchange Server Remote Code Execution Vulnerability

CVE-2021-27065 · Severity: critical · CVSS 7.8 · Exploited in the wild · Published 2021-11-03

Microsoft Exchange Server contains a remote code execution vulnerability involving improper limitation of a pathname to a restricted directory (path traversal). This vulnerability is a component of the ProxyLogon exploit chain and has been observed being exploited in the wild.

Technologies: Microsoft Exchange Server. Vendors: Microsoft.

Quick answers

Is CVE-2021-27065 exploited in the wild?: Yes. CVE-2021-27065 is known to be exploited in the wild, first recorded on 3 November 2021. Treat it as urgent.
How severe is CVE-2021-27065?: Critical severity, with a CVSS score of 7.8, published 3 November 2021.
Which products and versions are affected?: Microsoft Exchange Server 2013 Cumulative Update 21, 22, 23, Service Pack 1; Microsoft Exchange Server 2016 Cumulative Update 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19; Microsoft Exchange Server 2019 Cumulative Update 1, 2, 4, 5, 6, 7, 8.
Is there a fix for CVE-2021-27065?: No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2021-27065 attacked?: It is attacked with local access, in a network appliance.
Am I affected by CVE-2021-27065?: Check whether you run Microsoft Exchange Server. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Affected products

Microsoft Exchange Server 2013 Cumulative Update 21, 22, 23, Service Pack 1
Microsoft Exchange Server 2016 Cumulative Update 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19
Microsoft Exchange Server 2019 Cumulative Update 1, 2, 4, 5, 6, 7, 8

Timeline

2021-11-03: disclosed: Published date in advisory
2021-11-03: kev added: Added to CISA Known Exploited Vulnerabilities Catalog
2021-04-16: other: Original due date for remediation in CISA KEV record

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CVE-2021-27065: Microsoft Exchange Server Remote Code Execution Vulnerability

Quick answers

Affected products

Timeline

Related threats