CVE-2024-21384

Code execution via undisclosed use-after-free

Published Feb 13, 2024 · Updated Aug 10, 2026

Use-after-free in Microsoft OneNote in Office LTSC 2021 and Microsoft 365 Apps for enterprise allows attackers to execute code. Microsoft identifies freed-memory reuse in OneNote but has not disclosed the affected parser, object-lifetime error, or crafted input structure. Execution requires local user interaction with malicious content; successful exploitation runs code in that user context.

CVSS severity7.8
High
EPSS probability0.85%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Use-after-free in Microsoft OneNote in Office LTSC 2021 and Microsoft 365 Apps for enterprise allows attackers to execute code. Microsoft identifies freed-memory reuse in OneNote but has not disclosed the affected parser, object-lifetime error, or crafted input structure. Execution requires local user interaction with malicious content; successful exploitation runs code in that user context.

The record

CVE
CVE-2024-21384
Published
Feb 13, 2024
Updated
Aug 10, 2026
Vendor
Microsoft
Product
Microsoft Office LTSC 2021
Classifications
CWE-416, T1204
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 13, 2024CVE 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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=16.0.1 <https://aka.ms/OfficeSecurityReleases

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Microsoft · Microsoft Office LTSC 2021version=16.0.1 <https://aka.ms/OfficeSecurityReleases
Microsoft · Microsoft 365 Apps for enterpriseversion=16.0.1 <https://aka.ms/OfficeSecurityReleases

Published CVSS scores

7.8Microsoft CorporationCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free
T1204User Execution

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo