Cyber Resilience

CVE-2023-21714

Memory Safety in Microsoft 365 Apps

Published
14 February 2023
Modified
21 November 2024
Patch / advisory
CVSS Score v3.1 5.5
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:N/A:N
EPSS Score 0.0060 45th percentile
Risk Priority 47 floored blend · peak EPSS

Summary

CVE-2023-21714 is a medium-severity Out-of-bounds Read (CWE-125) vulnerability in Microsoft 365 Apps. Its CVSS base score is 5.5 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Cloud Instance Metadata API (T1552.005); ranked at the 45th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Microsoft Office Information Disclosure Vulnerability

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1552.005 Cloud Instance Metadata API Credential Access
Adversaries may attempt to access the Cloud Instance Metadata API to collect credentials and other sensitive data.
T1552.007 Container API Credential Access
Adversaries may gather credentials via APIs within a containers environment.
T1039 Data from Network Shared Drive Collection
Adversaries may search network shares on computers they have compromised to find files of interest.
T1530 Data from Cloud Storage Collection
Adversaries may access data from cloud storage.
T1552 Unsecured Credentials Credential Access
Adversaries may search compromised systems to find and obtain insecurely stored credentials.
T1552.001 Credentials In Files Credential Access
Adversaries may search local file systems and remote file shares for files containing insecurely stored credentials.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-32705Same product: Microsoft 365 Apps
CVE-2026-33822Same product: Microsoft 365 Apps
CVE-2026-20944Same product: Microsoft 365 Apps
CVE-2025-60728Same product: Microsoft 365 Apps
CVE-2023-21687Same vendor: Microsoft
CVE-2023-33162Same product: Microsoft 365 Apps
CVE-2024-49028Same product: Microsoft 365 Apps
CVE-2025-21383Same product: Microsoft 365 Apps
CVE-2023-21741Same product: Microsoft 365 Apps
CVE-2026-20946Same product: Microsoft 365 Apps

Affected Assets

microsoft
365 apps
all versions
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)
  • 8 hardening rules · 7 OS baselines
Validate
Prove the fix (OWASP ASVS)

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-668

Controls whether organization resources are exposed to external system spheres by permitting or prohibiting their use.

addresses: CWE-668

The control ensures information is not released into a security sphere where the recipient lacks matching access authorizations.

addresses: CWE-668

The control ensures information resources are not exposed to the incorrect (public) sphere through review and authorization.

addresses: CWE-668

Protects against data mining that would expose resources to unauthorized spheres by enforcing detection and controls.

addresses: CWE-668

Restricts information flows to ensure resources are not exposed to incorrect or unauthorized spheres.

addresses: CWE-668

Controlling internal connections prevents exposure of resources to unintended internal spheres.

addresses: CWE-668

Knowing exact processing and storage locations helps avoid exposure of resources to incorrect spheres.

addresses: CWE-668

The control prevents exposure of the media resource to the wrong security sphere.

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.AA-05 mostly match
prevents

Enforcing least-privilege authorizations directly prevents resources from being exposed outside their intended control sphere.

PR.PS-06 mostly match
prevents

Secure-development practices such as bounds checking and memory-safe languages directly prevent out-of-bounds reads.

ID.RA-01 partial match
prevents

Vulnerability scanning and recording can discover instances of out-of-bounds reads after code is deployed.

PR.IR-01 partial match
prevents

Network segmentation and unauthorized-access protections reduce the chance of resources being reachable by the wrong sphere.

PR.PS-02 partial match
prevents

Routine patching replaces vulnerable code containing out-of-bounds read flaws.

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 and acceptance includes fuzzing and static analysis that detect out-of-bounds read defects before release.

A.8.15 Logging partial match
finds

Logging can record evidence of an out-of-bounds read but does not prevent the weakness itself.

mitigates

Placing systems of differing trust levels into separate domains prevents resources from being placed in a sphere where they are reachable by unintended actors.

prevents

Secure development life cycle mandates input validation and bounds checking that directly prevent out-of-bounds reads.

prevents

Application security requirements include explicit bounds and memory-safety specifications that mitigate buffer over-reads.

prevents

Secure system architecture and engineering principles require memory-safe design patterns and runtime protections against out-of-bounds access.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 8 (2 rules)
  • V-248827 OL 8 must not have the rsh-server package installed. prevents CWE-668
  • V-248823 OL 8 must not have the telnet-server package installed. prevents CWE-668
RHEL 7 (1 rule)
  • V-204442 The Red Hat Enterprise Linux operating system must not have the rsh-server package installed. prevents CWE-668
Windows 10 (1 rule)
  • V-220967 The Debug programs user right must only be assigned to the Administrators group. prevents CWE-668
Windows 11 (1 rule)
  • V-253490 The "Debug programs" user right must only be assigned to the Administrators group. prevents CWE-668
Windows Server 2016 (1 rule)
  • V-225079 The Debug programs user right must only be assigned to the Administrators group. prevents CWE-668
Windows Server 2019 (1 rule)
  • V-205757 Windows Server 2019 Debug programs: user right must only be assigned to the Administrators group. prevents CWE-668
Windows Server 2022 (1 rule)
  • V-254500 Windows Server 2022 debug programs user right must only be assigned to the Administrators group. prevents CWE-668

References