Input validation error in Microsoft Exchange Server - CVE-2021-42321
Published: November 9, 2021 / Updated: November 16, 2022
Vulnerability identifier: #VU58055
CSH Severity: Critical
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:A/U:Red
CVE-ID: CVE-2021-42321
CWE-ID: CWE-20
Exploitation vector: Remote access
Exploit availability:
The vulnerability is being exploited in the wild
Vendor: Microsoft
Affected software:
Microsoft Exchange Server
Microsoft Exchange Server
Detailed vulnerability description
The vulnerability allows a remote user to compromise the affected system.
The vulnerability exists due to insufficient validation of cmdlet arguments. A remote user can run a specially crafted cmdlet and execute arbitrary commands on the system.
Note, the vulnerability is being actively exploited in the wild.
How to mitigate CVE-2021-42321
Install updates from vendor's website.