cbcvebase.
CVE-2024-38021
published 2024-07-09

CVE-2024-38021: Microsoft Outlook Remote Code Execution Vulnerability

PriorityP180high8.8CVSS 3.1
AVNACLPRNUIRSUCHIHAH
ITWVulnCheck KEV
Exploited in the wild
EPSS
3.50%
87.9th percentile
Microsoft Outlook Remote Code Execution Vulnerability

Affected

14 ranges
VendorProductVersion rangeFixed in
microsoftmicrosoft_365_apps_for_enterprise>= 16.0.1 < https://aka.ms/OfficeSecurityReleaseshttps://aka.ms/OfficeSecurityReleases
microsoftmicrosoft_office_2016>= 16.0.0 < 16.0.5456.100016.0.5456.1000
microsoftmicrosoft_office_2019>= 19.0.0 < https://aka.ms/OfficeSecurityReleaseshttps://aka.ms/OfficeSecurityReleases
microsoftmicrosoft_office_ltsc_2021>= 16.0.1 < https://aka.ms/OfficeSecurityReleaseshttps://aka.ms/OfficeSecurityReleases
microsoftoffice
microsoftoffice
microsoftoffice_long_term_servicing_channel
msrcmicrosoft_365_apps_for_enterprise_for_32-bit_systems
msrcmicrosoft_365_apps_for_enterprise_for_64-bit_systems
msrcmicrosoft_office_2016
msrcmicrosoft_office_2019_for_32-bit_editions
msrcmicrosoft_office_2019_for_64-bit_editions
msrcmicrosoft_office_ltsc_2021_for_32-bit_editions
msrcmicrosoft_office_ltsc_2021_for_64-bit_editions

Detection & IOCsextracted from sources · hover to see the quote

  • The vulnerability is triggered via a crafted malicious link that bypasses the Protected View Protocol in Microsoft Outlook, leading to RCE — monitor for Outlook processes spawning unexpected child processes after link interaction.
  • Exploitation requires user interaction — specifically a user allowing blocked content from an external sender. Alert on Outlook 'Allow' actions on externally-originated blocked content.
  • The Preview Pane is NOT an attack vector; focus detection on full message open and link-click events rather than previewPane rendering.
  • Successful exploitation grants high-privilege read/write/delete capability — post-exploitation activity may include file creation/deletion or credential access; monitor for anomalous OUTLOOK.EXE file I/O and privilege escalation indicators.
  • Affected products include Microsoft Office 2016 (32/64-bit), Office LTSC 2021, Microsoft 365 Apps for Enterprise, and Office 2019 — scope detection rules to these Office versions.
  • ·Exploitation is rated 'Exploitation More Likely' by Microsoft but has not been publicly exploited or disclosed as of the advisory date — prioritize patching over detection tuning.
  • ·The attack vector is Network and requires user interaction (UI:R); zero-click exploitation is not possible — detection should focus on user-initiated link-click events in Outlook.

CVSS provenance

nvdv3.18.8HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
vulncheck8.8HIGH
vendor_msrc8.8HIGH
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