Security Resilience

CVE-2023-33158

Memory Safety in Microsoft Office Long Term Servicing Channel 2021

Memory Safety
Published
11 July 2023
Modified
19 May 2026
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 0.0063 49th percentile
Risk Priority 58 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2023-33158 is a high-severity Wrap or Wraparound (CWE-191) vulnerability in Microsoft Office Long Term Servicing Channel. Its CVSS base score is 7.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique LSASS Memory (T1003.001); ranked at the 49th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability Data

Microsoft Excel Remote Code Execution Vulnerability

CWE(s)
CWE-191NVD-CWE-noinfo

Related Threats

MITRE ATT&CK Enterprise Techniques

T1003.001 LSASS Memory Credential Access
Adversaries may attempt to access credential material stored in the process memory of the Local Security Authority Subsystem Service (LSASS).
attack.mitre.org →
T1003.003 NTDS Credential Access
Adversaries may attempt to access or create a copy of the Active Directory domain database in order to steal credential information, as well as obtain other information about domain members such as devices, users, and access rights.
attack.mitre.org →
T1003.005 Cached Domain Credentials Credential Access
Adversaries may attempt to access cached domain credentials used to allow authentication to occur in the event a domain controller is unavailable.
attack.mitre.org →
T1003.008 /etc/passwd and /etc/shadow Credential Access
Adversaries may attempt to dump the contents of <code>/etc/passwd</code> and <code>/etc/shadow</code> to enable offline password cracking.
attack.mitre.org →
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.
attack.mitre.org →
T1008 Fallback Channels Command And Control
Adversaries may use fallback or alternate communication channels if the primary channel is compromised or inaccessible in order to maintain reliable command and control and to avoid data transfer thresholds.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-28285Same product: Microsoft 365 Apps
CVE-2023-33149Same product: Microsoft 365 Apps
CVE-2023-21735Same product: Microsoft 365 Apps
CVE-2023-36045Same product: Microsoft 365 Apps
CVE-2024-30101Same product: Microsoft 365 Apps
CVE-2023-33153Same product: Microsoft 365 Apps
CVE-2023-36895Same product: Microsoft 365 Apps
CVE-2023-21734Same product: Microsoft 365 Apps
CVE-2023-35372Same product: Microsoft 365 Apps
CVE-2023-36866Same product: Microsoft 365 Apps

Affected Assets

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

Mitigating Controls

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.

ID.RA-01 partial match
blocks

Vulnerability scanning and code analysis can surface underflow flaws after they are introduced.

PR.PS-02 partial match
blocks

Routine patching can remediate known underflow bugs once they are discovered in deployed software.

PR.PS-06 partial match
blocks

Secure SDLC practices directly prevent integer underflow defects via input validation, bounds checking, and static analysis.

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.5.14 Information transfer partial match
removes
A.5.15 Access control partial match
removes
A.5.16 Identity management partial match
removes
A.5.17 Authentication information partial match
removes
A.5.18 Access rights partial match
removes
A.8.10 Information deletion partial match
removes

References