CVE-2023-21764

LPE in Microsoft Exchange Server 2016 … 2019

LPE

Published

10 January 2023

Modified

21 November 2024

CVSS Score v3.1 7.8

Click a component to see what it means

Raw vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Score 0.0057 46th 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-2023-21764 is a high-severity Untrusted Search Path (CWE-426) vulnerability in Microsoft Exchange Server. Its CVSS base score is 7.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Path Interception by Unquoted Path (T1574.009); ranked at the 46th 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

🇪🇺 ENISA EUVD: EUVD-2023-25931

Vulnerability Data

Microsoft Exchange Server Elevation of Privilege Vulnerability

CWE(s): CWE-426 NVD-CWE-noinfo

Related Threats

MITRE ATT&CK Enterprise Techniques

T1574.009 Path Interception by Unquoted Path Stealth

Adversaries may execute their own malicious payloads by hijacking vulnerable file path references.

attack.mitre.org →

T1001.001 Junk Data Command And Control

Adversaries may add junk data to protocols used for command and control to make detection more difficult.

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 →

T1003.004 LSA Secrets Credential Access

Adversaries with SYSTEM access to a host may attempt to access Local Security Authority (LSA) secrets, which can contain a variety of different credential materials, such as credentials for service accounts.

attack.mitre.org →

T1003.006 DCSync Credential Access

Adversaries may attempt to access credentials and other sensitive information by abusing a Windows Domain Controller's application programming interface (API)(Citation: Microsoft DRSR Dec 2017) (Citation: Microsoft GetNCCChanges) (Citati…

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 →

Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-36778Same product: Microsoft Exchange Server

CVE-2024-26198Same product: Microsoft Exchange Server

CVE-2023-21763Same product: Microsoft Exchange Server

CVE-2023-38181Same product: Microsoft Exchange Server

CVE-2020-17144Same product: Microsoft Exchange Server

CVE-2023-21706Same product: Microsoft Exchange Server

CVE-2023-35368Same product: Microsoft Exchange Server

CVE-2024-21410Same product: Microsoft Exchange Server

CVE-2021-31195Same product: Microsoft Exchange Server

CVE-2022-41082Same product: Microsoft Exchange Server

Affected Assets

microsoft

exchange server

2016, 2019

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.

PR.PS-01 partial match

blocks

Hardened configuration baselines can enforce safe search paths and restrict environment variables that enable the weakness.

PR.PS-05 partial match

blocks

Preventing execution of unauthorized code directly blocks the malicious binaries that an untrusted search path would load.

PR.PS-06 partial match

blocks

Secure development practices include avoiding or sanitizing externally influenced search paths in application code.

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