CVE-2021-34474Network attack vector

Authenticated code execution via variable parsing

Published Jul 14, 2021 · Updated Aug 10, 2026

Remote code execution in Microsoft Dynamics 365 Business Central 16.0 and 17.0 allows remote authenticated users to execute code. Microsoft identifies variable parsing as the corrected area but has not disclosed the parser locus or exact unsafe operation on supplied data. Exploitation requires a highly privileged authenticated account and a crafted network request; successful execution can compromise service data and availability.

CVSS severity8.0
High
EPSS probability2.16%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Remote code execution in Microsoft Dynamics 365 Business Central 16.0 and 17.0 allows remote authenticated users to execute code. Microsoft identifies variable parsing as the corrected area but has not disclosed the parser locus or exact unsafe operation on supplied data. Exploitation requires a highly privileged authenticated account and a crafted network request; successful execution can compromise service data and availability.

The record

CVE
CVE-2021-34474
Published
Jul 14, 2021
Updated
Aug 10, 2026
Vendor
Microsoft
Product
Microsoft Dynamics 365 Business Central 2020 Release Wave 2 (On-Premise)
Classifications
T1190
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Jul 14, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 10, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=17.0 <17.0.27235

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

Microsoft · Microsoft Dynamics 365 Business Central 2020 Release Wave 2 (On-Premise)version=17.0 <17.0.27235
Microsoft · Microsoft Dynamics 365 Business Central 2020 Release Wave 1version=16.0 <16.0.27253

Published CVSS scores

8.0MicrosoftCVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H
7.2NVDCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
6.5NVDAV:N/AC:L/Au:S/C:P/I:P/A:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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