Cyber Resilience

CVE-2025-21408

Memory Safety in Microsoft Edge Chromium ≤ 133.0.3065.51

Memory Safety
Published
06 February 2025
Modified
11 February 2025
Patch / advisory
View advisory
CVSS Score v3.1 8.8
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS Score 0.013 68th percentile
Risk Priority 66 floored blend · peak EPSS

Summary

CVE-2025-21408 is a high-severity Type Confusion (CWE-843) vulnerability in Microsoft Edge Chromium. Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked in the top 32% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-8 (Security and Privacy Engineering Principles) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2025-21408 is a Remote Code Execution vulnerability in Microsoft Edge, the Chromium-based web browser. Published on 2025-02-06, it carries a CVSS v3.1 base score of 8.8 (AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H) and is associated with CWE-843 and NVD-CWE-noinfo.

The vulnerability enables exploitation over a network with low attack complexity, requiring no privileges but user interaction, such as clicking a malicious link. Attackers can achieve high impacts on confidentiality, integrity, and availability, allowing remote code execution on affected systems.

Microsoft's Security Response Center update guide at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21408 provides details on patches and mitigation steps.

EU & UK References

Vulnerability Data

Microsoft Edge (Chromium-based) Remote Code Execution Vulnerability

CWE(s)
CWE-843NVD-CWE-noinfo

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
attack.mitre.org →
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
attack.mitre.org →
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
attack.mitre.org →
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2024-38209Same product: Microsoft Edge Chromium
CVE-2026-58283Same product: Microsoft Edge Chromium
CVE-2026-58285Same product: Microsoft Edge Chromium
CVE-2026-66321Same product: Microsoft Edge Chromium
CVE-2026-58290Same product: Microsoft Edge Chromium
CVE-2026-58289Same product: Microsoft Edge Chromium
CVE-2026-58295Same product: Microsoft Edge Chromium
CVE-2025-21279Same product: Microsoft Edge Chromium
CVE-2024-38219Same product: Microsoft Edge Chromium
CVE-2023-36887Same product: Microsoft Edge Chromium

Affected Assets

microsoft
edge chromium
≤ 133.0.3065.51

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V1.5.2
  • V3.2.3
  • V15.3.5

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

Developer testing and evaluation (including fuzzing and type-aware analysis) directly finds type-confusion flaws before deployment.

SA-8 Security and Privacy Engineering Principles partial match

Engineering principles can require use of type-safe languages, static typing, and runtime type checks that structurally avoid allocating one type and accessing another.

SI-16 Memory Protection partial match

Memory-protection controls limit the blast radius when a type-confusion access occurs but do not stop the flaw itself.

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 SDLC practices directly prevent type-confusion flaws via safe typing, static analysis, and code review while the control itself addresses many additional 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.8.29 Security testing in development and acceptance mostly match
finds

Security testing in development can detect type-confusion vulnerabilities through fuzzing and static analysis.

A.8.25 Secure development life cycle partial match
prevents

Secure SDLC mandates type-safe design and review that can catch type-confusion flaws.

A.8.26 Application security requirements partial match
prevents

Application security requirements can specify strong typing and interface contracts that reduce type confusion.

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

Secure architecture principles promote type-safe languages and memory-safety mechanisms that mitigate type confusion.

A.8.28 Secure coding partial match
prevents

Secure coding standards directly forbid unsafe type casts and require static-analysis checks for type confusion.

References