Cyber Resilience

CVE-2025-21402

Microsoft Office 2024

Published
14 January 2025
Modified
19 May 2026
Patch / advisory
CVSS Score v3.1 7.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS Score 0.0065 48th percentile
Risk Priority 58 floored blend · peak EPSS

Summary

CVE-2025-21402 is a high-severity Improper Restriction of Names for Files and Other Resources (CWE-641) vulnerability in Microsoft Office. Its CVSS base score is 7.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Data from Local System (T1005); ranked at the 48th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SI-10 (Information Input Validation) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2025-21402 is a Remote Code Execution vulnerability in Microsoft Office OneNote. Published on January 14, 2025, it carries a CVSS v3.1 base score of 7.8 (AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H) and is associated with CWE-641 and NVD-CWE-noinfo.

The vulnerability requires local access (AV:L), low attack complexity (AC:L), no privileges (PR:N), and user interaction (UI:R), such as opening a malicious file. An attacker who can convince a user to interact with a specially crafted OneNote document can achieve remote code execution, resulting in high impacts to confidentiality, integrity, and availability (C:H/I:H/A:H) within the affected scope (S:U).

Microsoft's advisory on the MSRC Update Guide at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21402 provides details on mitigation, including available patches and security updates for affected OneNote versions.

EU & UK References

Vulnerability Data

Microsoft Office OneNote Remote Code Execution Vulnerability

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1005 Data from Local System Collection
Adversaries may search local system sources, such as file systems, configuration files, local databases, virtual machine files, or process memory, to find files of interest and sensitive data prior to Exfiltration.
T1083 File and Directory Discovery Discovery
Adversaries may enumerate files and directories or may search in specific locations of a host or network share for certain information within a file system.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-47173Same product: Microsoft Office
CVE-2025-21361Same product: Microsoft Office
CVE-2025-47953Same product: Microsoft Office
CVE-2024-30063Same vendor: Microsoft
CVE-2026-25177Same vendor: Microsoft
CVE-2026-50510Same vendor: Microsoft
CVE-2024-38173Same product: Microsoft Office
CVE-2024-49031Same product: Microsoft Office
CVE-2024-43609Same product: Microsoft Office
CVE-2023-35636Same product: Microsoft Office

Affected Assets

microsoft
office
2024
microsoft
office long term servicing channel
2021
microsoft
onenote
all versions

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

SI-10 requires validation of inputs used to construct resource names, directly stopping malformed or dangerous names from being accepted.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require input validation and sanitization to restrict resource names derived from untrusted data.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

finds

Security testing can detect improper filename handling but does not itself prevent the weakness.

prevents

Secure development life cycle mandates input validation and safe resource naming practices that directly prevent CWE-641.

prevents

Application security requirements include rules for handling untrusted input when constructing file or resource names.

prevents

Secure system architecture principles discourage unsafe resource naming but do not prescribe specific controls.

prevents

Secure coding standards explicitly require validation and sanitization of filenames derived from external input.

References