CVE-2024-21402

Local privilege elevation

Published Feb 13, 2024 · Updated Aug 10, 2026

Improper authorization in Microsoft Outlook within Microsoft 365 Apps for Enterprise allows local users to elevate privileges. Microsoft has not published the affected code path or the authorization operation that mishandles an unprivileged caller. A low-privileged local account is required, and successful exploitation permits reading and modifying data without interrupting service.

CVSS severity7.1
High
EPSS probability0.48%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper authorization in Microsoft Outlook within Microsoft 365 Apps for Enterprise allows local users to elevate privileges. Microsoft has not published the affected code path or the authorization operation that mishandles an unprivileged caller. A low-privileged local account is required, and successful exploitation permits reading and modifying data without interrupting service.

The record

CVE
CVE-2024-21402
Published
Feb 13, 2024
Updated
Aug 10, 2026
Vendor
Microsoft
Product
Microsoft 365 Apps for enterprise
Classifications
CWE-285, T1068
Attack vector
local
Privileges
authenticated

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

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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=16.0.1 <https://aka.ms/OfficeSecurityReleases

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

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

Published CVSS scores

7.1MicrosoftCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-285Improper Authorization
T1068Exploitation for Privilege Escalation

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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