Security Resilience

CVE-2023-21720

Memory Safety in Microsoft Edge Chromium ≤ 109.0.15.18.78

Memory Safety
Published
14 February 2023
Modified
19 August 2026
Patch / advisory
View advisory
CVSS Score v3.1 5.3
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:H
EPSS Score 0.012 68th percentile
Risk Priority 44 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-2023-21720 is a medium-severity Buffer Over-read (CWE-126) vulnerability in Microsoft Edge Chromium. Its CVSS base score is 5.3 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Protocol or Service Impersonation (T1001.003); ranked in the top 32% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability Data

Microsoft Edge (Chromium-based) Tampering Vulnerability

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

Related Threats

MITRE ATT&CK Enterprise Techniques

T1001.003 Protocol or Service Impersonation Command And Control
Adversaries may impersonate legitimate protocols or web service traffic to disguise command and control activity and thwart analysis efforts.
attack.mitre.org →
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 →
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 →
T1003.007 Proc Filesystem Credential Access
Adversaries may gather credentials from the proc filesystem or `/proc`.
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-2026-66312Same product: Microsoft Edge Chromium
CVE-2024-43595Same product: Microsoft Edge Chromium
CVE-2024-21337Same product: Microsoft Edge Chromium
CVE-2024-43587Same product: Microsoft Edge Chromium
CVE-2024-43578Same product: Microsoft Edge Chromium
CVE-2024-43579Same product: Microsoft Edge Chromium
CVE-2024-49023Same product: Microsoft Edge Chromium
CVE-2024-43472Same product: Microsoft Edge Chromium
CVE-2023-36741Same product: Microsoft Edge Chromium
CVE-2023-36735Same product: Microsoft Edge Chromium

Affected Assets

microsoft
edge chromium
≤ 109.0.15.18.78

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

PR.PS-02 partial match
blocks

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

PR.PS-06 partial match
blocks

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

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