#VU51169 Input validation error in Microsoft Exchange Server - CVE-2021-26858
Published: March 2, 2021 / Updated: April 1, 2021
Vulnerability identifier: #VU51169
Vulnerability risk: Critical
CVSSv4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:A/U:Red
CVE-ID: CVE-2021-26858
CWE-ID: CWE-20
Exploitation vector: Remote access
Exploit availability:
The vulnerability is being exploited in the wild
Vulnerable software:
Microsoft Exchange Server
Microsoft Exchange Server
Software vendor:
Microsoft
Microsoft
Description
The vulnerability allows a remote attacker to execute arbitrary code on the system.
The vulnerability exists due to insufficient validation of user-supplied input. A remote attacker can send specially crafted data to the Exchange server and execute arbitrary code on the system.
Note, this vulnerability is being actively exploited in the wild.
Remediation
Install updates from vendor's website.