Cyber Resilience

CVE-2023-21820

Memory Safety in Microsoft Windows Server 2008 r2

Memory Safety
Published
14 February 2023
Modified
21 November 2024
Patch / advisory
View advisory
CVSS Score v3.1 7.4
Click a component to see what it means
Raw vectorCVSS:3.1/AV:A/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
EPSS Score 0.0063 47th percentile
Risk Priority 62 floored blend · peak EPSS

Summary

CVE-2023-21820 is a high-severity Buffer Over-read (CWE-126) vulnerability in Microsoft Windows Server 2008. Its CVSS base score is 7.4 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique OS Credential Dumping (T1003); ranked at the 47th percentile by exploit likelihood (below the median); 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.

Windows Distributed File System (DFS) contains a remote code execution vulnerability tracked as CVE-2023-21820. The flaw affects the Windows DFS component and carries a CVSS 3.1 base score of 7.4 with the vector AV:A/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H, along with the weakness classification CWE-126.

An attacker positioned on an adjacent network who possesses low privileges and can induce limited user interaction may exploit the issue to execute arbitrary code, resulting in high impact to confidentiality, integrity, and availability on the affected system.

Microsoft’s Security Response Center advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21820 supplies official mitigation guidance and patch information for the vulnerability.

The associated EPSS score remains flat at 0.0616 with no material increase observed after disclosure.

EU & UK References

Vulnerability Data

Windows Distributed File System (DFS) Remote Code Execution Vulnerability

CWE(s)
CWE-126NVD-CWE-noinfo

Related Threats

MITRE ATT&CK Enterprise Techniques

T1003 OS Credential Dumping Credential Access
Adversaries may attempt to dump credentials to obtain account login and credential material, normally in the form of a hash or a clear text password.
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 →
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
attack.mitre.org →
T1552 Unsecured Credentials Credential Access
Adversaries may search compromised systems to find and obtain insecurely stored credentials.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-21811Same product: Microsoft Windows 10
CVE-2023-21813Same product: Microsoft Windows 10
CVE-2023-21701Same product: Microsoft Windows 10
CVE-2023-36581Same product: Microsoft Windows 10
CVE-2023-24857Same product: Microsoft Windows 10
CVE-2023-24858Same product: Microsoft Windows 10
CVE-2023-28266Same product: Microsoft Windows 10 1607
CVE-2023-24942Same product: Microsoft Windows 10 1607
CVE-2023-28267Same product: Microsoft Windows 10 1607
CVE-2023-33173Same product: Microsoft Windows 10 1607

Affected Assets

microsoft
windows 10
≤ 10.0.10240.19747
microsoft
windows 10 1607
≤ 10.0.14393.5717
microsoft
windows 10 1809
≤ 10.0.17763.4010
microsoft
windows 10 20h2
≤ 10.0.19042.2604
microsoft
windows 10 21h2
≤ 10.0.19044.2604
microsoft
windows 10 22h2
≤ 10.0.19045.2604
microsoft
windows 11 21h2
≤ 10.0.22000.1574
microsoft
windows 11 22h2
≤ 10.0.22621.1265
microsoft
windows server 2008
all versions, r2
microsoft
windows server 2012
all versions, r2
+3 more product configuration(s) — see NVD for full list

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-06 mostly match
prevents

Secure development practices directly prevent introduction of buffer over-read weaknesses.

ID.RA-01 partial match
prevents

Vulnerability identification processes can discover buffer over-read flaws via scanning or review.

PR.PS-02 partial match
prevents

Patching or replacing vulnerable software removes known instances of buffer over-read bugs.

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 can detect buffer over-reads before release.

A.8.25 Secure development life cycle partial match
prevents

Secure SDLC mandates input validation and bounds checking that can prevent buffer over-reads.

A.8.26 Application security requirements partial match
prevents

Application security requirements can specify buffer-size and bounds-checking rules.

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

Secure architecture principles include memory-safety and bounds-checking design choices.

A.8.28 Secure coding partial match
prevents

Secure coding standards directly require bounds-checked buffer access, mitigating over-reads.

References