Cyber Resilience

CVE-2025-21338

Memory Safety in Microsoft Office ≤ 2.93.24123014

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:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0048 39th percentile
Risk Priority 58 floored blend · peak EPSS

Summary

CVE-2025-21338 is a high-severity Integer Overflow or Wraparound (CWE-190) vulnerability in Microsoft Office. Its CVSS base score is 7.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 39th 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 SA-11 (Developer Testing and Evaluation) and SA-8 (Security and Privacy Engineering Principles) — 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-2025-21338 is a GDI+ Remote Code Execution vulnerability, published on 2025-01-14, with a CVSS v3.1 base score of 7.8 (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H). It is associated with CWE-190 and affects the GDI+ graphics component in Microsoft Windows systems.

The vulnerability can be exploited by a local attacker who has low privileges on the target system. Exploitation requires low complexity and no user interaction, allowing the attacker to execute arbitrary code in the context of the affected process, with high impacts on confidentiality, integrity, and availability.

Microsoft's advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21338 provides details on patches and mitigation steps for addressing this vulnerability.

EU & UK References

Vulnerability Data

GDI+ Remote Code Execution Vulnerability

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-21243Same product: Microsoft Windows 10 1507
CVE-2024-43623Same product: Microsoft Windows 10 1507
CVE-2025-50166Same product: Microsoft Windows 10 1507
CVE-2024-43628Same product: Microsoft Windows 10 1507
CVE-2024-43635Same product: Microsoft Windows 10 1507
CVE-2024-43641Same product: Microsoft Windows 10 1507
CVE-2025-21244Same product: Microsoft Windows 10 1507
CVE-2025-54110Same product: Microsoft Windows 10 1507
CVE-2024-49112Same product: Microsoft Windows 10 1507
CVE-2024-38144Same product: Microsoft Windows 10 1507

Affected Assets

microsoft
office
2024 · ≤ 2.93.24123014 · ≤ 16.0.14326.22175 · ≤ 16.0.18429.20000
microsoft
office long term servicing channel
2021
microsoft
windows 10 1507
≤ 10.0.10240.20890 · ≤ 10.0.10240.20890
microsoft
windows 10 1607
≤ 10.0.14393.7699 · ≤ 10.0.14393.7699
microsoft
windows 10 1809
≤ 10.0.17763.6775 · ≤ 10.0.17763.6775
microsoft
windows 10 21h2
≤ 10.0.19044.5371
microsoft
windows 10 22h2
≤ 10.0.19045.5371
microsoft
windows 11 22h2
≤ 10.0.22621.4751
microsoft
windows 11 23h2
≤ 10.0.22631.4751
microsoft
windows 11 24h2
≤ 10.0.26100.2894
+7 more product configuration(s) — see NVD for full list

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V5.2.6

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and evaluation (static analysis, fuzzing, unit tests) directly finds integer overflow defects before deployment.

Secure engineering principles require use of safe arithmetic constructs or language features that structurally eliminate integer overflow during calculation.

Input validation enforces bounds on values before arithmetic, stopping the conditions that trigger overflow or wraparound.

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 use of safe arithmetic, bounds checks, and testing that prevent integer overflows.

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 in development can detect integer overflows before release.

prevents

Secure SDLC mandates input validation and arithmetic checks that prevent integer overflows.

degrades

Application security requirements include bounds checking and safe arithmetic to avoid overflow conditions.

degrades

Secure architecture principles require defensive coding patterns that mitigate integer wraparound risks.

prevents

Secure coding standards explicitly forbid unsafe integer operations and mandate overflow-safe constructs.

References