Cyber Resilience

CVE-2023-28311

Memory Safety in Microsoft 365 Apps

Memory Safety
Published
11 April 2023
Modified
21 November 2024
Patch / advisory
View 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 0.027 85th percentile
Risk Priority 66 floored blend · peak EPSS

Summary

CVE-2023-28311 is a high-severity Heap-based Buffer Overflow (CWE-122) vulnerability in Microsoft 365 Apps. Its CVSS base score is 7.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked in the top 15% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

Deeper analysis AI-assisted summary

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

Microsoft Word contains a remote code execution vulnerability tracked as CVE-2023-28311 that stems from a heap-based buffer overflow, tracked under CWE-122. The flaw affects Microsoft Word and carries a CVSS 3.1 score of 7.8 with an attack vector that requires an attacker to supply a malicious file that the victim opens locally.

An unauthenticated attacker can exploit the issue by convincing a user to open a specially crafted document, after which arbitrary code executes with the privileges of the current user, resulting in full confidentiality, integrity, and availability impact on the affected system.

Microsoft security advisories hosted at the MSRC update guide for CVE-2023-28311 describe available patches and mitigation steps for supported versions of Word. The associated EPSS score rose from low values after disclosure to a peak of 0.1017 in January 2025 before receding to the current 0.0835, indicating a later surge in exploitation interest that warrants renewed attention.

EU & UK References

Vulnerability Data

Microsoft Word Remote Code Execution Vulnerability

CWE(s)
CWE-122NVD-CWE-noinfo

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.
attack.mitre.org →
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.
attack.mitre.org →
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
attack.mitre.org →
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
attack.mitre.org →
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-33152Same product: Microsoft 365 Apps
CVE-2023-33146Same product: Microsoft 365 Apps
CVE-2024-20677Same product: Microsoft 365 Apps
CVE-2023-29344Same product: Microsoft 365 Apps
CVE-2023-21738Same product: Microsoft 365 Apps
CVE-2025-27752Same product: Microsoft 365 Apps
CVE-2025-24057Same product: Microsoft 365 Apps
CVE-2025-54910Same product: Microsoft 365 Apps
CVE-2024-38169Same product: Microsoft 365 Apps
CVE-2025-54907Same product: Microsoft 365 Apps

Affected Assets

microsoft
365 apps
all versions
microsoft
office
2019
microsoft
office long term servicing channel
2021

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)
  • V1.4.1

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 full match
prevents

Secure-development practices directly require bounds checking and safe memory handling that prevent heap overflows.

ID.RA-01 partial match
prevents

Vulnerability scanning and recording can discover heap-overflow flaws but does not prevent their introduction in code.

PR.PS-02 partial match
prevents

Timely patching removes known heap-overflow instances after they exist.

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.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing in development and acceptance can detect heap overflows before release.

A.8.25 Secure development life cycle partial match
prevents

Secure development lifecycle mandates practices that reduce the likelihood of introducing heap overflows.

A.8.26 Application security requirements partial match
prevents

Application security requirements can specify bounds-checking and safe memory APIs that mitigate heap overflows.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure architecture and engineering principles include memory-safety and input-validation controls that address heap overflows.

A.8.28 Secure coding partial match
prevents

Secure coding standards directly prescribe techniques (safe functions, bounds checks) that prevent heap-based buffer overflows.

A.8.32 Change management none match
none

Change management ensures controlled deployment of fixes for discovered heap-overflow vulnerabilities.

References