CVE-2023-21706

Description

Microsoft Exchange Server Remote Code Execution Vulnerability

Overview

State: PUBLISHED
Assigner (CNA): microsoft
CVSS severity: HIGH
CVSS score: 8.8 / 10
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
Effective score: 8.8 / 10 HIGH source: CNA overview
MSRC score: 8.8 / 10 HIGH MS rating: Important · Remote Code Execution
CWE(s): CWE-502
Reserved: 2022-12-13
Published: 2023-02-14 08:00 UTC
Last updated: 2023-02-14 08:00 UTC
Source: https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2023/21xxx/CVE-2023-21706.json
Linked Threat: CVE-2023-21706 — Microsoft Exchange Server Remote Code Execution Vulnerability

NVD triage scoring NVD CVE 2.0

Layer NVD adds on top of the CNA's CVE record — published / last-modified timestamps, exploitability / impact subscores, and the FIRST.org EPSS probability that this CVE will be exploited in the wild in the next 30 days.

NVD published: 2023-02-14 20:15:13 UTC
NVD last modified: 2026-06-17 05:33:43 UTC
NVD CVSS v3.1: 8.8 / 10 HIGH source: secure@microsoft.com
NVD CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Exploitability subscore: 2.8 / 10
Impact subscore: 5.9 / 10
EPSS score: 0.0406 (probability of exploitation in next 30 days)
EPSS percentile: 89.59% vs all CVEs — higher = more likely to be exploited, as of 2026-07-27

European Union Vulnerability Database ENISA EUVD

ENISA's official EU repository for curated vulnerability intelligence. Carries a separate identifier (EUVD-YYYY-NNNN) and frequently exposes an earlier-published description + CVSS than NVD does.

EUVD ID: EUVD-2023-25873
Assigner: microsoft
Published: Feb 14, 2023, 7:32:44 PM
Updated: Jan 1, 2025, 12:40:46 AM
EUVD base score (CVSS 3.1): 8.8 / 10
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
EUVD-reported EPSS: 2.3900
Vendors: Microsoft
Products: Microsoft Exchange Server 2019 Cumulative Update 12 (15.02.0 <15.02.1118.025)

Microsoft Exchange Server 2013 Cumulative Update 23 (15.00.0 <15.00.1497.047)

Microsoft Exchange Server 2019 Cumulative Update 11 (15.02.0 <15.02.0986.041)

Microsoft Exchange Server 2016 Cumulative Update 23 (15.01.0 <15.01.2507.021)
Aliases: GHSA-8v8w-cp35-xxq5

ENISA description: Microsoft Exchange Server Remote Code Execution Vulnerability

EUVD references (1)

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21706

Microsoft Security Response Center MSRC

Microsoft's vendor-authoritative record from the Security Update Guide — its own CVSS score, impact, severity rating, exploit assessment, and KB-article fixes. Refreshed 2026-08-11 01:49 UTC (source: CVRF).

MS severity: Important
Impact: Remote Code Execution
MS CVSS base score: 8.8 / 10 (temporal 7.7)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
Exploit assessment: Publicly Disclosed:No;Exploited:No;Latest Software Release:Exploitation More Likely;DOS:N/A
Release: 2023-Feb

Microsoft remediations / KB articles (5)

5023038 — Vendor Fix / Security Update (fixed build 15.02.1118.025)
5023038 — Update
5023038 — Vendor Fix / Security Update (fixed build 15.01.2507.021)
5023038 — Vendor Fix / Security Update (fixed build 15.02.0986.041)
5023038 — Vendor Fix / Security Update (fixed build 15.00.1497.047)

Microsoft FAQ (2)

According to the CVSS metric, the attack vector is network (AV:N) and the user interaction is none (UI:N). What is the target used in the context of the remote code execution?

The attacker for this vulnerability could target the server accounts in an arbitrary or remote code execution. As an authenticated user, the attacker could attempt to trigger malicious code in the context of the server's account through a network call.

According to the CVSS metric, privileges required is low (PR:L). Does the attacker need to be in an authenticated role on the Exchange Server?

Yes, the attacker must be authenticated.

Affected products (4)

Vendor	Product	Versions	Platforms
Microsoft	Microsoft Exchange Server 2019 Cumulative Update 12	`15.02.0` (affected)	x64-based Systems
Microsoft	Microsoft Exchange Server 2016 Cumulative Update 23	`15.01.0` (affected)	x64-based Systems
Microsoft	Microsoft Exchange Server 2019 Cumulative Update 11	`15.02.0` (affected)	x64-based Systems
Microsoft	Microsoft Exchange Server 2013 Cumulative Update 23	`15.00.0` (affected)	x64-based Systems

Affected products — CPE 2.3 (4) NVD

NVD's normalized CPE 2.3 matchers, used by vendor tools (vulnerability scanners, asset managers) for automated detection. Compare with the CNA's free-text "Affected products" section above.

cpe:2.3:a:microsoft:exchange_server:2013:cumulative_update_23:*:*:*:*:*:*
cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_23:*:*:*:*:*:*
cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_11:*:*:*:*:*:*
cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_12:*:*:*:*:*:*

Vendor references (1)

References embedded in the original CVE record by the assigning CNA.

Microsoft Exchange Server Remote Code Execution Vulnerability vendor-advisory

Web references (10)

DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.

5023038 msrc
5023038 msrc
5023038 msrc
5023038 msrc
MSRC update guide: CVE-2023-21706 msrc
https://support.microsoft.com/en-us/help/5023038 rapid7:support.microsoft.com
https://www.cve.org/CVERecord?id=CVE-2023-21706 rapid7:www.cve.org
https://attackerkb.com/topics/CVE-2023-21706 rapid7:attackerkb.com
https://support.microsoft.com/help/5023038 rapid7:support.microsoft.com
http://cwe.mitre.org/data/definitions/502.html rapid7:cwe.mitre.org

NVD-tagged references (2)

Reference list NVD curates from the CNA record, vendor advisories, and third-party reports. The tag chips below are NVD's analyst-assigned categories.

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21706 secure@microsoft.com PatchVendor Advisory
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21706 af854a3a-2127-422b-91ae-364da2661108 PatchVendor Advisory

Remediations (17)

Remediations are stored against the linked Threat row; the list below is deduplicated across both pages.

Rapid7 — Solution

rapid7

msft-kb5023038-0114c451-a5b6-4e1a-8da5-f20a2bc43f10

2026-05-28 22:58 UTC
Security Updates - Red Hat Customer Portal

web:access.redhat.com

Learn about our open source products, services, and company. You are here

2026-06-04 06:13 UTC
‎Google Gemini

web:gemini.google.com

Meet Gemini, Google's AI assistant. Get help with writing, planning, brainstorming, and more. Experience the power of generative AI.

2026-06-04 06:13 UTC
NVD - Vulnerabilities

web:nvd.nist.gov

Vulnerabilities All vulnerabilities in the NVD have been assigned a CVE identifier and thus, abide by the definition below. CVE defines a vulnerability as: "A weakness in the computational logic (e.g., code) found in software and hardware components that, when exploited, results in a negative impact to confidentiality, integrity, or availability. Mitigation of the vulnerabilities in this ...

2026-06-04 06:13 UTC
Update Chrome now: Critical bugs could let attackers run code

web:www.malwarebytes.com

This Chrome update fixes critical flaws attackers could exploit through malicious websites, but not the "Browser Fetch" vulnerability.

2026-06-04 06:13 UTC
Patch Tuesday - May 2026 - Rapid7

web:www.rapid7.com

Microsoft is publishing 137 vulnerabilities on May 2026 Patch Tuesday, including critical RCE in Netlogon and the Windows DNS client.

2026-06-04 06:13 UTC
Patch Tuesday June 2026: Security Updates & CVE Analysis

web:zecurit.com

Get the complete breakdown of Microsoft's June 2026 Patch Tuesday. We analyze the latest security updates and all critical CVEs .

2026-06-04 06:13 UTC
Mitigation vs Remediation in Cybersecurity | SecurityScorecard

web:securityscorecard.com

Mitigation : Minimizing impact and exposure Mitigation , on the other hand, focuses on minimizing the impact of a cybersecurity threat or vulnerability rather than eliminating it entirely. While remediation seeks to address the root cause, mitigation aims to reduce the risk and consequences associated with the threat.

2026-05-22 05:45 UTC
Microsoft March 2026 Patch Tuesday fixes 2 zero-days, 79 flaws

web:www.bleepingcomputer.com

Today is Microsoft's March 2026 Patch Tuesday with security updates for 79 flaws, including 2 publicly disclosed zero-day vulnerabilities.

2026-05-22 05:45 UTC
A guide to vulnerability remediation vs mitigation | @Bugcrowd

web:www.bugcrowd.com

Vulnerability mitigation is typically considered a temporary or interim solution. While mitigation measures can reduce the immediate risk associated with vulnerabilities, they may not provide a permanent fix . Organizations should aim to prioritize and plan for complete vulnerability remediation whenever feasible and allocate resources accordingly.

2026-05-22 05:45 UTC
CVE: Common Vulnerabilities and Exposures

web:www.cve.org

At cve .org, we provide the authoritative reference method for publicly known information-security vulnerabilities and exposures

2026-05-22 05:45 UTC
'Reboot Your PC'—Microsoft Changes 'Most Windows Devices' In June

web:www.forbes.com

Microsoft starts expiring critical Secure Boot certificates in just 2 weeks.

2026-05-22 05:45 UTC
Microsoft Patch Tuesday May 2026 - 120 Vulnerabilities Fixed, Including ...

web:cybersecuritynews.com

Microsoft's May 2026 Patch Tuesday lands with a heavy enterprise focus, fixing 120 vulnerabilities across Windows, Office, Azure, developer tools, and Microsoft 365 apps, including 29 remote code execution (RCE) flaws rated Critical.

2026-05-22 05:45 UTC
Vulnerability Remediation vs. Mitigation: What are the Differences ...

web:www.secure.com

Learn the difference between vulnerability remediation and mitigation , and how a risk-based strategy can strengthen your security posture.

2026-05-22 05:45 UTC
Oracle Critical Patch Update Advisory - April 2026

web:www.oracle.com

This Critical Patch Update contains 481 new security patches across the product families listed below. Please note that an MOS note summarizing the content of this Critical Patch Update and other Oracle Software Security Assurance activities is located at April 2026 Critical Patch Update: Executive Summary and Analysis.

2026-05-22 05:45 UTC
Security Update Guide - Loading - Microsoft

web:portal.msrc.microsoft.com

The Security Update Guide provides information on the latest Microsoft security updates, helping users understand and address potential vulnerabilities effectively.

2026-05-22 05:45 UTC
Vulnerability Remediation vs Mitigation: Which Strategy Wins in ...

web:securityboulevard.com

Organizations must decide how to tackle vulnerabilities—through remediation , mitigation , or a combination of both. But which strategy is more effective? This blog explores the nuances of vulnerability remediation vs mitigation , their respective benefits, and how to choose the right approach.

2026-05-22 05:45 UTC

AI Forensic Analysis

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Raw JSON

The full cvelistV5 record. Download as CVE-2023-21706.json.

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