Microsoft Exchange Server RCE (ProxyShell)

critical Nessus Plugin ID 152458


The remote mail server is affected by a remote code execution vulnerability.


The Microsoft Exchange running on the remote host is affected by a remote code execution vulnerability. An unauthenticated remote attacker can exploit this to execute arbitrary code.


Microsoft has released the following security updates to address this issue:

See Also

Plugin Details

Severity: Critical

ID: 152458

File Name: exchange_proxyshell.nbin

Version: 1.26

Type: remote

Agent: windows

Family: Windows

Published: 8/11/2021

Updated: 8/15/2022

Supported Sensors: Nessus Agent

Risk Information


Risk Factor: Critical

Score: 9


Risk Factor: Critical

Base Score: 10

Temporal Score: 8.7

Vector: AV:N/AC:L/Au:N/C:C/I:C/A:C

Temporal Vector: E:H/RL:OF/RC:C

CVSS Score Source: CVE-2021-34473


Risk Factor: Critical

Base Score: 9.8

Temporal Score: 9.4

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: E:H/RL:O/RC:C

Vulnerability Information

CPE: cpe:/a:microsoft:exchange_server

Required KB Items: installed_sw/Outlook Web Access

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 4/13/2021

Vulnerability Publication Date: 7/13/2021

CISA Known Exploited Dates: 11/17/2021

Exploitable With

Metasploit (Microsoft Exchange ProxyShell RCE)

Reference Information

CVE: CVE-2021-34473

MSKB: 5001779

MSFT: MS21-5001779