Cyber Posture

CVE-2025-21279

Medium

Published: 06 February 2025

Published
06 February 2025
Modified
11 February 2025
KEV Added
Patch
CVSS Score 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
EPSS Score 0.0091 75.9th percentile
Risk Priority 14 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-21279 is a medium-severity Type Confusion (CWE-843) vulnerability in Microsoft Edge Chromium. Its CVSS base score is 6.5 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Drive-by Compromise (T1189); ranked in the top 24.1% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified are NIST 800-53 SI-2 (Flaw Remediation) and RA-5 (Vulnerability Monitoring and Scanning).

Threat & Defense at a Glance

What attackers do: exploitation maps to Drive-by Compromise (T1189) and 1 other technique. What defenders deploy: see the NIST 800-53 controls recommended below.
Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

prevent

Directly mitigates the RCE vulnerability by requiring timely application of Microsoft patches for the specific flaw in Edge as referenced in the update guide.

preventdetect

Provides defense-in-depth through malicious code protection mechanisms that detect and block exploit payloads targeting the browser RCE.

detect

Identifies unpatched Edge installations vulnerable to this CVE via regular vulnerability scanning.

MITRE ATT&CK Enterprise TechniquesAI

T1189 Drive-by Compromise Initial Access
Adversaries may gain access to a system through a user visiting a website over the normal course of browsing.
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
Why these techniques?

Browser RCE with UI:R enables drive-by compromise (T1189) and client-side exploitation for code execution (T1203).

Confidence: MEDIUM · MITRE ATT&CK Enterprise v18.1

NVD Description

Microsoft Edge (Chromium-based) Remote Code Execution Vulnerability

Deeper analysisAI

CVE-2025-21279 is a Remote Code Execution vulnerability affecting Microsoft Edge (Chromium-based). Published on 2025-02-06, it has a CVSS v3.1 base score of 6.5 (AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N) and is associated with CWE-843 and NVD-CWE-noinfo.

Remote attackers can exploit this vulnerability over the network with low attack complexity and no privileges required, though user interaction is necessary. Successful exploitation enables high-impact confidentiality violations, such as unauthorized access to sensitive data, without affecting integrity or availability.

Microsoft has published an update guide with mitigation details for CVE-2025-21279 at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21279.

Details

CWE(s)

Affected Products

microsoft
edge chromium
≤ 133.0.3065.51

CVEs Like This One

CVE-2025-21342Same product: Microsoft Edge Chromium
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CVE-2025-62554Same vendor: Microsoft
CVE-2025-21326Same vendor: Microsoft
CVE-2025-53143Same vendor: Microsoft
CVE-2025-53145Same vendor: Microsoft
CVE-2025-53144Same vendor: Microsoft

References