CVE-2025-21357: Microsoft Outlook Remote Code Execution Vulnerability

Overview

Severity
Medium (CVSS 6.7)
CVSS Vector
CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
Category
Remote Code Execution
Exploit Status
Not Exploited
Exploitation Likelihood
Less Likely
Patch Tuesday
2025-Jan
Released
2025-01-14
Last Updated
2025-01-27
EPSS Score
0.34% (percentile: 57.1%)

FAQ

According to the CVSS metric, the attack complexity is high (AC:H) and privileges required are low (PR:L). What does that mean for this vulnerability? An attacker must gain access to the victim user's Microsoft Outlook account by compromising or stealing their login credential and then install a malicious form prior to exploiting the vulnerability successfully. According to the CVSS metric, user interaction is required (UI:R). What interaction would the user have to do? A user needs to be tricked into opening malicious files. According to the CVSS metric, the attack vector is local (AV:L). Why does the CVE title indicate that this is a remote code execution? The word Remote in the title refers to the location of the attacker. This type of exploit is sometimes referred to as Arbitrary Code Execution (ACE). The attack itself is carried out locally. This means an attacker or victim needs to execute code from the local machine to exploit the vulnerability. Is the Preview Pane an attack vector for this vulnerability? No, the Preview Pane is not an attack vector.

Affected Products (10)

Microsoft Office

  • Microsoft Office 2019 for 32-bit editions
  • Microsoft Office 2019 for 64-bit editions
  • Microsoft 365 Apps for Enterprise for 32-bit Systems
  • Microsoft 365 Apps for Enterprise for 64-bit Systems
  • Microsoft Office LTSC 2021 for 64-bit editions
  • Microsoft Office LTSC 2021 for 32-bit editions
  • Microsoft Office LTSC 2024 for 32-bit editions
  • Microsoft Office LTSC 2024 for 64-bit editions
  • Microsoft Outlook 2016 (32-bit edition)
  • Microsoft Outlook 2016 (64-bit edition)

Security Updates (2)

Acknowledgments

<a href="https://www.linkedin.com/in/arnoldosipov/">Arnold Osipov</a> with <a href="https://www.morphisec.com/">Morphisec</a>, <a href="https://www.linkedin.com/in/smgoreli/">Michael Gorelik</a> with <a href="https://www.morphisec.com/">Morphisec</a>, <a href="https://x.com/seungyun_le2">SeungYun LEE</a> with <a href="https://www.kitribob.kr/">bObffice (BOB13th)</a>, <a href="https://x.com/zeroboo1227">JunHyuk Im</a> with <a href="https://www.kitribob.kr/">bObffice (BOB13th)</a>, <a href="https://www.linkedin.com/in/기연-정-48635a335/">Kiyeon Jeong</a> with <a href="https://www.kitribob.kr/">bObffice (BOB13th)</a>, <a href="https://x.com/kimjor22">JongGeon KIM</a> with <a href="https://www.kitribob.kr/">bObffice (BOB13th)</a>, <a href="https://x.com/lmksecurity">Jeongmin Choi</a> with <a href="https://www.kitribob.kr/">bObffice (BOB13th)</a>

Revision History

  • 2025-01-14: Information published.
  • 2025-01-27: Added an FAQ to indicate that the Preview Pane is not affected for this CVE. This is an informational change only.