CVE-2021-27065 Microsoft Exchange Server Remote Code Execution

Exploited in the wild High 7.8 Published Updated

Attackers can exploit a path traversal flaw in Microsoft Exchange Server to execute arbitrary code remotely.

Exploited in the wild
Since 3 Nov 2021
Login needed
Not needed
Attackable
Local or same network only
Victim action needed
A user has to click or open something
Fix
None listed

What is CVE-2021-27065?

CVE-2021-27065 is a high-severity path traversal vulnerability in Microsoft Exchange Server, published on 2 Mar 2021. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

Official description

Microsoft Exchange Server Remote Code Execution Vulnerability

Weakness: CWE-22

Which versions are affected by CVE-2021-27065?

It affects 1 product.

Products include Microsoft Exchange Server.

How do I fix CVE-2021-27065?

No fix has been published for CVE-2021-27065 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 3 May 2022.

Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.

Is CVE-2021-27065 being exploited?

Yes. Attackers have exploited CVE-2021-27065 in the wild since at least 3 Nov 2021, including in ransomware campaigns.

Public exploit code: 1 Metasploit module, 1 Exploit-DB entry and 1 proofs of concept on GitHub.

All Microsoft Exchange Server vulnerabilities

Sources

Also known as GHSA-rwm8-8c4x-v87q.

Is CVE-2021-27065 in your software?

Upload an SBOM and sbomify checks it against every vulnerability here, every day.

Check your SBOMs for free